idle surging and rich help
11-27-2008, 06:35 PM
#1
Advanced
Thread Starter
Join Date: Apr 2007
Location: Italy Mestre-Venice
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
idle surging and rich help
read the precedent dialogue between John Speake and me you must begin with the last message and after go up.
Thank for your help.
Hello Massimo,
I suggest you try starting a thread on Rennlist 928 Forum. Wally and many other 928 experts are on there, and will help you sort out the problem.
http://forums.rennlist.com/ then go to "watercooled" and then "928"
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Wednesday, November 26, 2008 7:57 PM
Subject: Fw: possible MAF failure from Italy
Hi.John.
Can you help me.
I have driven my car to the workshop.
When i drive my car if i disconnect some vacum hoses the car run bit well but the idle always hunt up and down.
I have tested my injectors all injectors are ok.
Can you try to help me with the help of other people like for example wally plumley at 928 specialist or other experts on 928.
Greetings.
Massimo.
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, October 16, 2008 7:33 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
i ear "clik"-"clik"-"clik" and after the "clik" Stop
Now if i start the car the engine run rough for 1-2 second and after stall and i ear the fuel pump for about another 2 second.
About three days ago i have started the engine and the engine goes very rough not regular with all cylinder.
Yestarday i have started the engine and the engine stall after 1-2 second after for one time i ear a big noise like "stok" now if i start the car i don't ear metallic noise or strange noise.
I hope that my engine was not broken.i hope that the "stok" was a fuel explosion in the exhaust.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, October 16, 2008 3:15 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo
Do you hear a rapid clicking in the engine when you switch on the igntion, but not try to start the car ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, October 16, 2008 12:33 PM
Subject: Re: possible MAF failure from Italy
Hello John.
Now If i start the car after 1 second the engine stop. The spark plug are very wet.
Greetings.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Saturday, September 20, 2008 10:21 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
When you carried out these tests, was the car at normal operating temperature ?
Everything points to the mixture being too rich, but why ?
Can you check fuel pressure ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Saturday, September 20, 2008 12:48 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
Today i have make some test on my car.
If i disconnect the MAF the engine stop the car do not goes into limp home mode the engine stop and does not restart.
if i disconnect the O2 sensor nothing change if i disconnect temperature sensor II nothing change.
I have created some false air leaks by disconnecting the blue/black check valve and the air pump/exhaust valve and the car goes well. idle is more stable but not perfect engine respond well at the throttle opening.
I have checked vacum at fuel regulator and dampers and vacum is present and there'is no sign of fuel in the vacum tube.
without the air filter the car goes bad than before.
Thank you.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, September 18, 2008 1:39 PM
Subject: Re: possible MAF failure from Italy
o2 sensor?
>>>>>>>>>>>>>>>
Possibly, but this can be eliminated by unplugging etc.
<<<<<<<<<<<<<<<
air leaks in the intake?
>>>>>>>>>>>>>
This would give a too high idle speed
>>>>>>>>>>>>>>
fuel injectors?
>>>>>>>>>>>>>>>
Possible, although this will trigger the igntion protectionn relay
>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<
air leaks in the exhaust?
<<<<<<<<<<<<<
Maybe, especially near the O2 sensor, but can be eliminated by unplugging O2 sensor.
<<<<<<<<<<<<<<
idle speed valve?
>>>>>>>>>>>>>>>>
Possible
<<<<<<<<<<<<<<
trhottle position sensor?
>>>>>>>>>>>
Possible.
<<<<<<<<<<<<
I have another question for you.
Can you diagnostic and repair an Ferrari 208 turbo ABS ecu.
I work in a mesarati workshop and we have a problem with an 208 turbo
>>>>>>>>>>>>
Sorry, no I can't help with this...
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, September 18, 2008 12:27 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
Re-read my precedent mails.
Thank you.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Wednesday, September 17, 2008 10:53 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
Sorry for the delay.
You would have to connect wires into the cableforms of LH and EZK to obtain a diagnostic connection.
Or use two 35 way break out boxes, suitably wired to a diagnostic connector.
To make just a plug in device would be very expensive.
I can send you the information of what you need to wire into the cables, but I don't have a diagnostic socket as fitted to the car.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, September 16, 2008 9:17 PM
Subject: Fw: possible MAF failure from Italy
Hi.JOHN.
Can you answer me at my precedent e-mail?
I have another question for you.
Can you diagnostic and repair an Ferrari 208 turbo ABS ecu.
I work in a mesarati workshop and we have a problem with an 208 turbo.
Regards.
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Sunday, September 14, 2008 3:53 PM
Subject: Re: possible MAF failure from Italy
i tested the connection between the coding plug and the ezk and lh ecu all connection was ok.
which could be faults:
o2 sensor?
air leaks in the intake?
fuel injectors?
air leaks in the exhaust?
idle speed valve?
trhottle position sensor?
in these days i have used some injector cleaner and the car run well than before.
but when the car is at operating temperature the idle go up and down.
when the car is cold when i press the gas pedal the rpm go up but after go down under the normal idle sometimes the rpm goes to zero and after the car return to idle.
I have re-checked the temperature sensor at the lh ecu plug and at teh ezk ecu plug and the values are normal i have re-checked the idle speed contact end the full load contact for idle speed contact about 8 ohm when throttle is close and after infinity ohm for the full load contact infinity when the throttle is close and about 70-80 ohm when the gas pedal is full down (i think that the full load contact don't work well).
i think that the car is always a little rich on the exhaust but i do not have big blake smoke when the car is at operating temperature the i sniff fuel smell and after catalyst smell like when the cars are in the motorway like burned smell
respectively when the idle goes up and down.
Regards.
Massimo.
You would be able to build for me a wiring for the diagnosis that i can insert in the lh and ezk plug?
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Monday, September 08, 2008 10:51 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
I believe that the 19way diagnostic connector for >MY89 is part of the digi-dash wiring loom.
Also, I believe that the 12way diagnostic connector for MY87/88 is part of the wiring loom for LH and EZK, so yes, I think this is why your car
does not have the 12way or 19 way connector.
I assume you are wanting to conenct a diagnostic tester to your car to try and determine the problem..... it will probably only tell you "O2 loop too rich".
Did you test that the coding plug is connecting through to all the connections it makes to the LH ECU ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Friday, September 05, 2008 9:23 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
I have checked the eletrical wiring model year '88 12 way diagnosis plug and model year '89 19 way diagnosi plug.
On my car there is a possibility that the ezk and lh ecu and the ecu main cable was upgraded to model year '89 with ignition relè.
My questions are where the 19 way diagnosis plug cable originates ( see sheet 4 wiring diagram m.y '98 in attached)?
I can upgrade also the diagnosis plug because i think that the 19 way diagnosis plug wires not origanets from the ecu main cable.
attention i have the non digital instrument cluster
If i had on my car the correct type of ecu my engine should goes well?
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Saturday, August 23, 2008 4:32 PM
Subject: Re: possible MAF failure from Italy
Your LH is /13 for MY 90/91, so that is OK. EZK is also for MY 90/91. Both with diagnostics, hence the "DIA" code on the labels.
Your code plug seems to be early type ROW with cats, manual transmission.
Have a good holiday !
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Saturday, August 23, 2008 2:03 PM
Subject: Re: possible MAF failure from Italy
I send you photos ( code labels) of LH ecu EZK ecu and coding plug.
Today i go in Spain for my holidays.
I come back 30 August.
Regards.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Saturday, August 23, 2008 2:02 PM
Subject: Re: possible MAF failure from Italy
See my replies inserted below... in red
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Saturday, August 23, 2008 12:24 PM
Subject: Re: possible MAF failure from Italy
Hi.
I bought the car with ignition relè fitted.
if you see the 1987 wiring diagram on the diagnosis plug there's written
"tester plug only factory" and on my parts cataloge CD there is written on
the -88 LH main cable 92860701504 "wiring harness see q-information GR.2
NR.3/86"
If you can read all my precedent long e-mail.
Thank you.
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Saturday, August 23, 2008 11:06 AM
Subject: Re: possible MAF failure from Italy
It's very strange. I have never known an 87 ot 88 928 that doesn't have that connector. The 19way circular type under the cover at the side of the passenger side seat came in with model year 89 (i.e. from August 88).Did you fit the ignition protection relay ? It requires a different engine wiring loom, with the two sets of injectors seperated out for the relay.
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Friday, August 22, 2008 11:41 PM
Subject: Re: possible MAF failure from Italy
no i have write that i don't have find the 12 way connector.See the photos.
Regards.
Massimo
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Friday, August 22, 2008 11:46 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo
It's late now, I'll answer your questions tommorrow.
You have found a 12way connector, it may be the correct one. Does it have just one lead going to it, and a cover with pins (like a coding plug, but with no wires to the pins ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Friday, August 22, 2008 8:54 PM
Subject: Re: possible MAF failure from Italy
I have replaced the two coils with this code 92860211600 different from my old coils in the plug hole and for this reason i have replaced the two wires from coil to distributor i think that my old coils was 94460211500.I have replaced coils with 92860211600 because this coil is for option code M298/M299 and my car is CAT.I read on rennlist that the coils is different only at the plug hole and for this reason when you change with 92860211600 you must also change the plug lead to the distributor. I think that the coils are interchangeable try to search at Bosch online catalogue http://ecat-online.bosch.de/ and say me what do you think about it.
>>>>>>>>>>>>>>>>>
OK - that seems logical and OK
>>>>>>>>>>>>>>>>>>>
I have removed the fuse and relè panel and i did not find any 12 way
diagnosis plug and on the LH and EZK main cable there is not any 12 way
plug.
See the photos in attached.
>>>>>>>>>>>>>>>>>>>>
Very strange...
Which is the version of my LH unit and which diagnosis capacity has?
>>>>>>>>>>>>>>>>>>
I can't remember, but I think you should be able to see the label on the box....... 928 618 123 /11 or /13 will have diagnosis. /10 will not.
<<<<<<<<<<<<<<<<<<<<<<<<<
I did not find any circular 19 way plug near the cooling flap ecu between
the passenger seat and the door.
What do you think about it?
>>>>>>>>>>>>>>>>
I am not sure which cableform has the diagnostic conenctor in it. The engine to LH/EDZK cableform must have been upgraded to the 89 version for the prtotection relay. But you should have one version or the other... I assume there are no cut wires ?
<<<<<<<<<<<<<<<<<<<<<
Do you know something about the LH injector self cleaning function or it
does not exist?
>>>>>>>>>>>>>>>>>>>>
There is no such system on the 928
<<<<<<<<<<<<<<<<<<
My car whit ignition relè it had always run good except for the times when i
have hunting idle up and and resolved this defect by press the relè socket on the relè.Now the car with the relè inserted or bypassed run in the same way.Do you think that there's a possibility that the timing is gone bad?
>>>>>>>>>>>>>>>>>>>
The timing is set by a toothed gear on the engine, so timing cannot change. It is also most unlikely your valve timing has changed due to jumping a tooth.
<<<<<<<<<<<<<<<<<<<
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Thursday, August 21, 2008 10:50 AM
Subject: Re: possible MAF failure from Italy
For O2 test i have disconncted the O2 sensor plug and i have connected ltmeter to the single pin and ground at the top of the fuse panel.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
the O2 sesnor has to be plugged into the car to make a sensible measurement (so the loop is complete). You have to insert a wire into
the single pin socket to make a measurement weith the plug connected.
<<<<<<<<<<<<<<<<<
I don't find 12 way connector today i have removed the fuse and relè panel and i had find only connected plug not 12 way disconnected plug.I suppose that the 12 way plug wire originates from the LH plug cable.
It's correct?
>>>>>>>>>>>>>>>>>>
From the main LH/EZK cable form. The 12way plug has acover on it. It looks identical to the coding plug exccept it is longer.
<<<<<<<<<<<<<<<<<<<<
Yes my ignition relè it's connected but i don't have fitted it if you
remeber i said you that sometimes some months ago the car sometimes has idle hunting up and down and when i pressed the relè base on the ignition relè the idle returned normal. Yesterday i tried to bypass the relè i had connected A1-A2-87 but the engine run in the same way idle up and down Tonight i send you a photo of ignition relè wire.Do you think that there's a possibility that the car was converted with CAT when the car was in Germany.
>>>>>>>>>>>>>>>>
Maybe, but the car was running OK before ?
>>> <<<<<<<<<<<<<<<<<
There's a possibility that i have fitted the wrong type of coils (coils are
new) for model year 89 with CAT?
>>>>>>>>>>>>>>>>>>>>
PET says for MY 87 part 944 602 115 00 and from MY88 onwards 92860203900. But I don't know what the difference is.
Which side is the coil that you changed ? (as viewed sitting in driver's seat)
<<<<<<<<<<<<<<<<<
When i turn my ignition key i ear some click-click-click coming from the
engine i think on the left bank (cylinder 5-6-7-8) after 1 second the
click-click-click stop.
>>>>>>>>>>>>>>>>>>>>>>
??
John
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Wednesday, August 20, 2008 9:13 PM
Subject: Re: possible MAF failure from Italy
Hello
Your O2 sensor voltages are not correct, you meansured them with the
sensor still connected to the LH ECU ? See page 24-219 of the workshop
manual. In normal use the voltage with oscillate between 01.v and 800mV.
You are correct, your car is MY 88. It will have the 12way connector
that I described. It has probably been buried behind the LH/EZK ECUs.
If you have fitted the igntion protection relay (did you do this change?) then you should add the 150 ohm resistor, although this is only used when the relay is triggered.
See page 24-222 of the WSM. It is strange that only some plugs are
blacker than the others. You have the igntion protection relay in circuit
(i.e. not replaced with a bypass link ?
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Wednesday, August 20, 2008 7:53 PM
Subject: Re: possible MAF failure from Italy
I have measured the 02 sensor single pin and ground the value at the
idle was 0.01v and after with the engine at about 3000-4000 rpm the values have increased at 2.0v 3.0v after i have stopped the vaules test.
I don't undertstand because if i disconnect the O2 sensor and make battery reset nothing change the engine run in the same way.Today i have searched the diagnosis plug but I did not find anything my car first registration in 1987 vin number WPOZZZ92ZJS840062 and for this reason i assume that my car is model year 1988.My car have ignition monitoring sistem and the car is catalyzed but my coding plug don't have 150ohm resistance between pin 7 and pin 8 of the coding plug.In attached the spark plugs photos. (spark plug at cylinder 6-7-8 are more black)
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Wednesday, August 20, 2008 12:54 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
I certainly sounds as though the O2 loop is not in control at idle, and maybe also higher in the rpm/load range.....
You can meaure the O2 sensor voltage to see if the loop is working OK.It should move from about 0.2v to 0.9v quite quickly. If the voltage is high or low continuously, then maybe the O2 sensor is faulty. (Only measure O2 sensor volts when engine is at normal working temperature.)
If one injector is not flowing correctly, then there will be excess oxygen into the exhaust and the loop may be trying to obtain the correct CO at the sensor, this would give a rich mixture in the engine.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Wednesday, August 20, 2008 9:33 AM
Subject: Re: possible MAF failure from Italy
Yesterday i have make a gas tester on my car (I work in a Maserati workshop i'm a office man not a mechanic but i'm a fan of the vintage car i have got a maserati biturbo SI '87 and a mini de tomaso turbo '87) the CO is very high and the car is rich at the idle without black smoke on the tailpipe.Yesterday I had put in my gas tank one bottle of injector cleaner and the car goes a little better than before i have run for about 20 km and the engine does not cut out but my idle always hunting up and down yesterday i have checked the sparks plug after a little fast run around the workshop and the spark plugs returned clean. today i send you a photo of the spark plugs.There' is a possibility that my car have a rich situation only at the idle.Yesterday i returned at my home without the coding plug inserted and the car goes in the same way no difference but i don't remeber if i had make a battery reset when i have disconnected the coding plug.
My chief that is a Ferrari and Maserati mechanic suggested me to revise the
injectors
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Wednesday, August 20, 2008 9:59 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
No, the car will not run correctly without the 8 pin coding plug
inserted. The car will run very rich.
The diagnosis plug is a larger 12 way version of the coding plug. It
should be fixed to the same mounting plate that holds the LH and EZK ECUs
Sometimes they become detached from the plate, and can be out of
sight under or behind the plate.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Tuesday, August 19, 2008 10:19 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
I have one question for you.
The car can run without the 8 pin coding plug inserted?
Where is the diagnosis plug in my car?
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Tuesday, August 12, 2008 1:37 PM
subject: Re: possible MAF failure from Italy
OK Massimo, thanks for letting me know.
Good luck with your fault finding !
Regards
Jhon Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Tuesday, August 12, 2008 12:31 PM
Subject: Re: possible MAF failure from Italy
Hi.
Thank you John i have received the package today.
When i find a solution if you want we can write on rennlist.
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Tuesday, August 05, 2008 2:12 PM
Subject: Re: possible MAF failure from Italy
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Monday, August 04, 2008 8:52 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
It would improve throttle response somewhat. Max power will not be affected much because the S4 is fuelled rather on the rich side of nominal as standard.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Monday, August 04, 2008 7:32 PM
Subject: Re: possible MAF failure from Italy
Hi. John.
I have one question for you.
My MAF is 2,4 % aged if you had better calibrated it the engine would go better or not would be there any difference?
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Monday, August 04, 2008 4:54 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
Thank you for your Paypal. I posted your parts back to you today.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Sunday, August 03, 2008 1:33 PM
Subject: Re: possible MAF failure from Italy
Hi. John.
Are you 100% sure that my LH and EZK are good?
Now i can try to find my failure in others parts of my car?
My car have the ignition protection relay and if you remember i said you that when i had my drivers coil wire not well connected the car had started to run in four cylinder mode.But now there are not led illuminated on the protection ralay.Now my MAF is better calibrated than before?
My adress is:
MASSIMO CISTERNINO
VIA G.B. GRASSI, 2
30170 MESTRE-VENEZIA (VE)
ITALY.
I pay you with paypall.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Sunday, August 03, 2008 11:20 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
OK, MY 88, but all my comments below except the one ".......Does your car have the igntion protection relay ? With the red and green LEds ? I think so. Have you checked that these are not being illuminated ?..............." are applicable to your car.I have finished temperature testing your LH ECU, and I confirm that I have found no problems with any of your units
I am ready to send them back to you.
My charges are 90 Euro for testing, plus 18 Euro for the MAF
screen and locking ring. Postage and VAT will add 40 Euro.
Total is therefore 148 Euro. Can you pay by Paypal ? My Paypal
email address is info@jdsporsche.com
Please give me you return address for delviery.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Sunday, August 03, 2008 1:43 AM
Subject: Re: possible MAF failure from Italy
Hi.John.
My car is model year '88 but my car have ignition protection relay my coding plug have this code 92860743300 (WITHOUT RESISTANCE between pin 7 and pin 8 and without pin 8) this code is for rest of the world cars with manual transmission and catalityc converter on one of my manuals say that the car that have ignition protection relay must have coding plug 92860743800 with a resistance of 150 ohm between pin 7and pin 8.My manual say about ignition protection relay this:
Even with the undocking of a circuit injection four-cylinder aspire air, the probe lambda recognize a surplus of air and within the cylinder intact, adjusting an air / petrol towards enrichment. To avoid this,disconnecting a circuit ignition is turned off even the lambda probe.inserting the ignition contact 15 of the relay is tension through LH ECU. At the contact relay AL (this cable leads to contact 28 of LH ECU) with ignition on there is ground.The codification, with or without CAT for lh ECU runs through the positive or the mass contact 28 of lh ECU itself, with ignition on LH ECU is encoded by the AL contact relay for the service without CAT.If the engine is started to contact 61 of the relay there is the alternator tension thus there is tension at contact AL and thus the LH ECU is codified for the service with CAT.
If an ignition circuit fails and contact relay opens is given ground at contact AL and the LH ECU switches to service without CAT.But in cars without CAT the CO is regulated at the idle through a potentiometer, but this potentiometer is not available in cars with CAT (lambda self/auto regulating), with the ignition protection relay and thus lambda adjustment switching from the regulation with lambda probe to regulation without lambda probe , through a resistance of 150 ohm in the coding plug of the LH ECU is assigned a fixed value or a replacement value to the LH ECUt for ensure the functioning of the engine at the idle.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Saturday, August 02, 2008 12:56 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
I am in the middle of more tests on your LH. So far I have not found any problems.
When the car's water temperature is below about 70deg C, then the
O2 sensor is not used, the car runs open loop. So O2 sensor is
not a possible problem at that time. And not the reason for a very rich mixture.
Does your car have the igntion protection relay ? With the red and green LEds ? I think so. Have you checked that these are not being illuminated ?
Are you quite sure the spark plug leads are on the correct cylinders ?Have you checked fuel pressure ? Also check fuel flow rate, at the return to the tank at the rear (there is a test in the workshop manual).
Also make sure that there is no fuel in the vacuum lines to the fuel pressure regulator, or the two fuel dampers. Sometimes the diaphram in them can split and fuel gets into the engine vacuum lines.
I see you have been measuring for vacuum leaks - good.
Have you measured battery volts with engine ruuning ?
Check carefully that the coding plug conatcts are OK. This is
the 8 way plug/socket on the LH/EZK mounting plate.Pin 1 is ground (chassis). Pins 2,4 & 7 are also linked to ground via pin 1.
Make sure all ground points are a good connection - less than
1 ohm from LH and EZK 35way plugs.
I will have finished testing today.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Saturday, August 02, 2008 12:21 AM
Subject: Re: possible MAF failure from Italy
Ok John.but the defect start to manifest it when i start the car with rich mixture with strong smell of fuel (my eyes burning) and with small accelerator openings the engine hesitate and after go down with a low idle and after return at the idle.
When the engine is heating the idle start surging up and down and after when for example i go out for a tour around my garage the engine die at the stop. I think that could be a multiple failure O2 sensor plus ignition modules or plus an air leak (i have found one air leak under the intake think betwen the spider and the throttle body on the top) or plus alternator or plus fuel pump or fuel filter or check valve (fuel filter and check valve are new about 4000 km but there is a possibility that i have clogged it when i went out for a tour and my fuel tank was empty) or i don't know???????????????????
what do you think about my problem if MAF (have you calibratedit?) is ok my LH is ok and my EZK is ok???????????????
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Friday, August 01, 2008 11:18 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
No, I haven't found anything. I was hoping to test more today, but I just didn't have time. I will be doing more test tommorrow. I always seem to be working at weekends :-)
I am going to concentrate on your LH ECU. I will temperature test it just to make sure there isn't an obscure fault that is not obvious normally. I will use the "SharkTuner" to do these tests, as it tells me exactly what is going on inside the ECU.
By the end of the weekend I will be able to tell you if there
is anything wrong with your units.....
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Friday, August 01, 2008 7:37 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
Have you got any news for me? Have you find some defect?
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Friday, August 01, 2008 10:31 AM
Subject: Re: possible MAF failure from Italy
Ah ! OK :-)
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Thursday, July 31, 2008 8:36 PM
Subject: Re: possible MAF failure from Italy
Venice is very beautiful it is a unique city.
If you come again to Venice you can take a hotel in Mestre to pend less. I ive in Mestre-Venezia.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Thursday, July 31, 2008 7:48 PM
Subject: Re: possible MAF failure from Italy
OK, thanks for that info. I will do more testing later today and tommorrow. My wife and daughter were in Venice earlier this year. They still talk about it :-)
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 6:13 PM
Subject: Re: possible MAF failure from Italy
I have checked the resistance at the lh and ezk 35way plugs and was in the normal range i have also checked the sensor in a cup of hot water and the values are normal at 80 c° 60 c° and ecc....... The problem of my car are rich running immediately when the car is cold with black spark and a lot of condensation water in my exhaust my idle surging up and down and my car cut out when it is hot and when cut out the rev counter not drop instantly my idle go down with warning light on and my car cut out. when the car is very hot it is hard to start if i start without gas pedal pressed my car start and after immediately cut outs.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, July 31, 2008 5:37 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
I can supply new screens and lock rings. The price for both (new) would be 18 Euro plus VAT.I am wondering if the problem with your car is linked to the work you did with Temp 2 sensor ? Have you check the temp 2 resistances
at the LH and EZK disconnected 35way plugs ?
I will do some more tests on your LH and EZK later
today.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 12:57 PM
Subject: Re: possible MAF failure from Italy
Ok John.
Have you got used parts or you must order it at porsche code 92811090100 and 92811090200 ?
If my MAF my LH and my EZK are good.
What may be the fault?
Did I already told the work I was doing (replaced radiator expansion tank with new cap,connector of temp II sensor new coils with updated coil cable my car in origin mount first type of coil with old type of cable) on my car before they manifest failure.It happened that one day to prove my car I think I have remained almost without gasoline because my car was not good if the accelerator was full depressed after I made gasoline the car was going as before.Few months ago I have started another car with cables attached on my 928.A lot of few months ago the idle surging up and down and the problem is resolved if I touched the base of the ignition monitoring
system relè.Have you got any idea ?
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, July 31, 2008 11:54 AM
Subject: Re: possible MAF failure from Italy
The screens do help to create a laminar airflow over the MAF sensor heated wire. Some people do remove the lower screen thinking it"improves
airflow" but this is not a good idea.I have never heard for removing the screen causing the
issues you have (rich running) but I think you should have that screen
in place.
I can supply and fit.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 10:15 AM
Subject: Re: possible MAF failure from Italy
i don't know i have removed the MAF and i have find
only the top screen.
---- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, July 31, 2008 11:09 AM
Subject: Re: possible MAF failure from Italy
I have one question - why has the bottom screen
been removed
from your MAF ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 9:46 AM
Subject: Re: possible MAF failure from Italy
Hi.John.
Have you received my package?
Regards.
Massimo.
--- Original Message -----
From: JDSPorsche
To: massimo
Sent: Tuesday, July 29, 2008 9:52 PM
Subject: Re: possible MAF failure from Italy
Ok thanks for letting me know !
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, July 29, 2008 8:35 PM
Subject: Re: possible MAF failure from Italy
Hi.
You should receive the package tomorrow.
Regards.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Monday, July 28, 2008 4:50 PM
Subject: Re: possible MAF failure from Italy
OK Massimo,
I willl et you know as soon as they
arrive here.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Monday, July 28, 2008 3:21 PM
Subject: Re: possible MAF failure from Italy
Hi.
I have decided to send you for a test
the EZK ecu also.
Regards.
Massimo.
I think that the package arrive to you
about Wednesday or Thursday.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Sunday, July 27, 2008 12:01 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
OK, I will let you know as soon as I receive your parts, and what I find with testing them.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Saturday, July 26, 2008 8:17 PM
Subject: Re: possible MAF failure from Italy
Hi.
Next week i want ship you my MAF and my LH ECU.Please give me confirmation.
Regards.
Massimo
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Tuesday, July 15, 2008 11:13 PM
Subject: Re: possible MAF failure from Italy
Unless you have a severe misfire caused by faulty output stages etc, which would allow unburnt fuel into
the exhaust,then no, I doubt this is the problem with your car.
It does sound as though, for some reason, the O2 loop is not working as it should......
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, July 15, 2008
9:49
PM
Subject: Re: possible MAF
failure
from Italy
the ignition trigger or the ignition final output stages.see the photo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Tuesday, July 15, 2008
10:38 PM
Subject: Re: possible MAF
failure from Italy
I don't know quite what you mean by "output stages" - please explain...
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, July 15, 2008
7:57 PM
Subject: Re: possible MAF
failure from Italy
OK this help me. thank you.and the final output stages?
wich the typical sign of fault in this component and if you know the
non typical?
----- Original Message -----
From: JDSPorsche To: massimo
Sent: Tuesday, July 15, 2008 7:33 PM
Subject: Re: possible MAF failure from Italy
I have tested the full load contact and the ohm value is about 20 ohm ( the workshop say that the value must be minor of 10 ohm) and also say: " if the full load contact fail the control unit geberates a load threshold by way of the air mass sensor. Values below this load are the same as if the switch were open,values above it are the same as if the switch were closed.What does mean this?
Hi
It means that if the full load switch fails,the LH ECU can still recognise a high engine load (i.e. throttler well open) and hence provides the enrichment required. It won't be as precise as if the LH ECU also received the full load switch input as well.....the ohm value that i have tested were initially minor and after that i have pressed the gas pedal few times the value increased.There are known problems with the throttle switches. Solder joints inside can fail, and then the full load switch can even go open circuit at all times. What do you think about a possibile fault
output stages or alternator a fault on this component can make rich mixture?.
The LH ECU monitors battery voltage and if it is below the normal voltage increases the injector opening times in order to compensate for the extra time the injectors take to open with a low voltage. Conversely, as battery volts rise, the injector on times are reduced.Normal opening time to open an injector is about 1mS. This time is added to the actual time the injector is required to delvier fuel when fully open.So you will only get unwated enrichment if the LH ECU sees a low battery voltage, or has a fault that makes it think a normal voltage is lower than it actually is.
Hope this helps ?
Regards John
----- Original Message ---
From: massimo
To: JDSPorsche
Sent: Tuesday, August 19, 2008 1:24 PM
Subject: Re: possible MAF failure from Italy
Hi.I have tested the temperature sensor II in a cup of hot water with a termocouple attached on it and the ohm values are normal.I have also tested the engine temperature sensor II with plug inserted and the values are different like if there are some resistance in parallel the value with the ezk and lh ecu plug detached are normal.The value of temperature sensorII are the
same with plug inserted and with plug not inserted?I have cleaned all spark plugs.
Thank for your help.
Hello Massimo,
I suggest you try starting a thread on Rennlist 928 Forum. Wally and many other 928 experts are on there, and will help you sort out the problem.
http://forums.rennlist.com/ then go to "watercooled" and then "928"
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Wednesday, November 26, 2008 7:57 PM
Subject: Fw: possible MAF failure from Italy
Hi.John.
Can you help me.
I have driven my car to the workshop.
When i drive my car if i disconnect some vacum hoses the car run bit well but the idle always hunt up and down.
I have tested my injectors all injectors are ok.
Can you try to help me with the help of other people like for example wally plumley at 928 specialist or other experts on 928.
Greetings.
Massimo.
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, October 16, 2008 7:33 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
i ear "clik"-"clik"-"clik" and after the "clik" Stop
Now if i start the car the engine run rough for 1-2 second and after stall and i ear the fuel pump for about another 2 second.
About three days ago i have started the engine and the engine goes very rough not regular with all cylinder.
Yestarday i have started the engine and the engine stall after 1-2 second after for one time i ear a big noise like "stok" now if i start the car i don't ear metallic noise or strange noise.
I hope that my engine was not broken.i hope that the "stok" was a fuel explosion in the exhaust.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, October 16, 2008 3:15 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo
Do you hear a rapid clicking in the engine when you switch on the igntion, but not try to start the car ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, October 16, 2008 12:33 PM
Subject: Re: possible MAF failure from Italy
Hello John.
Now If i start the car after 1 second the engine stop. The spark plug are very wet.
Greetings.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Saturday, September 20, 2008 10:21 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
When you carried out these tests, was the car at normal operating temperature ?
Everything points to the mixture being too rich, but why ?
Can you check fuel pressure ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Saturday, September 20, 2008 12:48 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
Today i have make some test on my car.
If i disconnect the MAF the engine stop the car do not goes into limp home mode the engine stop and does not restart.
if i disconnect the O2 sensor nothing change if i disconnect temperature sensor II nothing change.
I have created some false air leaks by disconnecting the blue/black check valve and the air pump/exhaust valve and the car goes well. idle is more stable but not perfect engine respond well at the throttle opening.
I have checked vacum at fuel regulator and dampers and vacum is present and there'is no sign of fuel in the vacum tube.
without the air filter the car goes bad than before.
Thank you.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, September 18, 2008 1:39 PM
Subject: Re: possible MAF failure from Italy
o2 sensor?
>>>>>>>>>>>>>>>
Possibly, but this can be eliminated by unplugging etc.
<<<<<<<<<<<<<<<
air leaks in the intake?
>>>>>>>>>>>>>
This would give a too high idle speed
>>>>>>>>>>>>>>
fuel injectors?
>>>>>>>>>>>>>>>
Possible, although this will trigger the igntion protectionn relay
>>>>>>>>>>>>>>>>>
<<<<<<<<<<<<<<
air leaks in the exhaust?
<<<<<<<<<<<<<
Maybe, especially near the O2 sensor, but can be eliminated by unplugging O2 sensor.
<<<<<<<<<<<<<<
idle speed valve?
>>>>>>>>>>>>>>>>
Possible
<<<<<<<<<<<<<<
trhottle position sensor?
>>>>>>>>>>>
Possible.
<<<<<<<<<<<<
I have another question for you.
Can you diagnostic and repair an Ferrari 208 turbo ABS ecu.
I work in a mesarati workshop and we have a problem with an 208 turbo
>>>>>>>>>>>>
Sorry, no I can't help with this...
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, September 18, 2008 12:27 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
Re-read my precedent mails.
Thank you.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Wednesday, September 17, 2008 10:53 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
Sorry for the delay.
You would have to connect wires into the cableforms of LH and EZK to obtain a diagnostic connection.
Or use two 35 way break out boxes, suitably wired to a diagnostic connector.
To make just a plug in device would be very expensive.
I can send you the information of what you need to wire into the cables, but I don't have a diagnostic socket as fitted to the car.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, September 16, 2008 9:17 PM
Subject: Fw: possible MAF failure from Italy
Hi.JOHN.
Can you answer me at my precedent e-mail?
I have another question for you.
Can you diagnostic and repair an Ferrari 208 turbo ABS ecu.
I work in a mesarati workshop and we have a problem with an 208 turbo.
Regards.
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Sunday, September 14, 2008 3:53 PM
Subject: Re: possible MAF failure from Italy
i tested the connection between the coding plug and the ezk and lh ecu all connection was ok.
which could be faults:
o2 sensor?
air leaks in the intake?
fuel injectors?
air leaks in the exhaust?
idle speed valve?
trhottle position sensor?
in these days i have used some injector cleaner and the car run well than before.
but when the car is at operating temperature the idle go up and down.
when the car is cold when i press the gas pedal the rpm go up but after go down under the normal idle sometimes the rpm goes to zero and after the car return to idle.
I have re-checked the temperature sensor at the lh ecu plug and at teh ezk ecu plug and the values are normal i have re-checked the idle speed contact end the full load contact for idle speed contact about 8 ohm when throttle is close and after infinity ohm for the full load contact infinity when the throttle is close and about 70-80 ohm when the gas pedal is full down (i think that the full load contact don't work well).
i think that the car is always a little rich on the exhaust but i do not have big blake smoke when the car is at operating temperature the i sniff fuel smell and after catalyst smell like when the cars are in the motorway like burned smell
respectively when the idle goes up and down.
Regards.
Massimo.
You would be able to build for me a wiring for the diagnosis that i can insert in the lh and ezk plug?
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Monday, September 08, 2008 10:51 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
I believe that the 19way diagnostic connector for >MY89 is part of the digi-dash wiring loom.
Also, I believe that the 12way diagnostic connector for MY87/88 is part of the wiring loom for LH and EZK, so yes, I think this is why your car
does not have the 12way or 19 way connector.
I assume you are wanting to conenct a diagnostic tester to your car to try and determine the problem..... it will probably only tell you "O2 loop too rich".
Did you test that the coding plug is connecting through to all the connections it makes to the LH ECU ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Friday, September 05, 2008 9:23 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
I have checked the eletrical wiring model year '88 12 way diagnosis plug and model year '89 19 way diagnosi plug.
On my car there is a possibility that the ezk and lh ecu and the ecu main cable was upgraded to model year '89 with ignition relè.
My questions are where the 19 way diagnosis plug cable originates ( see sheet 4 wiring diagram m.y '98 in attached)?
I can upgrade also the diagnosis plug because i think that the 19 way diagnosis plug wires not origanets from the ecu main cable.
attention i have the non digital instrument cluster
If i had on my car the correct type of ecu my engine should goes well?
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Saturday, August 23, 2008 4:32 PM
Subject: Re: possible MAF failure from Italy
Your LH is /13 for MY 90/91, so that is OK. EZK is also for MY 90/91. Both with diagnostics, hence the "DIA" code on the labels.
Your code plug seems to be early type ROW with cats, manual transmission.
Have a good holiday !
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Saturday, August 23, 2008 2:03 PM
Subject: Re: possible MAF failure from Italy
I send you photos ( code labels) of LH ecu EZK ecu and coding plug.
Today i go in Spain for my holidays.
I come back 30 August.
Regards.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Saturday, August 23, 2008 2:02 PM
Subject: Re: possible MAF failure from Italy
See my replies inserted below... in red
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Saturday, August 23, 2008 12:24 PM
Subject: Re: possible MAF failure from Italy
Hi.
I bought the car with ignition relè fitted.
if you see the 1987 wiring diagram on the diagnosis plug there's written
"tester plug only factory" and on my parts cataloge CD there is written on
the -88 LH main cable 92860701504 "wiring harness see q-information GR.2
NR.3/86"
If you can read all my precedent long e-mail.
Thank you.
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Saturday, August 23, 2008 11:06 AM
Subject: Re: possible MAF failure from Italy
It's very strange. I have never known an 87 ot 88 928 that doesn't have that connector. The 19way circular type under the cover at the side of the passenger side seat came in with model year 89 (i.e. from August 88).Did you fit the ignition protection relay ? It requires a different engine wiring loom, with the two sets of injectors seperated out for the relay.
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Friday, August 22, 2008 11:41 PM
Subject: Re: possible MAF failure from Italy
no i have write that i don't have find the 12 way connector.See the photos.
Regards.
Massimo
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Friday, August 22, 2008 11:46 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo
It's late now, I'll answer your questions tommorrow.
You have found a 12way connector, it may be the correct one. Does it have just one lead going to it, and a cover with pins (like a coding plug, but with no wires to the pins ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Friday, August 22, 2008 8:54 PM
Subject: Re: possible MAF failure from Italy
I have replaced the two coils with this code 92860211600 different from my old coils in the plug hole and for this reason i have replaced the two wires from coil to distributor i think that my old coils was 94460211500.I have replaced coils with 92860211600 because this coil is for option code M298/M299 and my car is CAT.I read on rennlist that the coils is different only at the plug hole and for this reason when you change with 92860211600 you must also change the plug lead to the distributor. I think that the coils are interchangeable try to search at Bosch online catalogue http://ecat-online.bosch.de/ and say me what do you think about it.
>>>>>>>>>>>>>>>>>
OK - that seems logical and OK
>>>>>>>>>>>>>>>>>>>
I have removed the fuse and relè panel and i did not find any 12 way
diagnosis plug and on the LH and EZK main cable there is not any 12 way
plug.
See the photos in attached.
>>>>>>>>>>>>>>>>>>>>
Very strange...
Which is the version of my LH unit and which diagnosis capacity has?
>>>>>>>>>>>>>>>>>>
I can't remember, but I think you should be able to see the label on the box....... 928 618 123 /11 or /13 will have diagnosis. /10 will not.
<<<<<<<<<<<<<<<<<<<<<<<<<
I did not find any circular 19 way plug near the cooling flap ecu between
the passenger seat and the door.
What do you think about it?
>>>>>>>>>>>>>>>>
I am not sure which cableform has the diagnostic conenctor in it. The engine to LH/EDZK cableform must have been upgraded to the 89 version for the prtotection relay. But you should have one version or the other... I assume there are no cut wires ?
<<<<<<<<<<<<<<<<<<<<<
Do you know something about the LH injector self cleaning function or it
does not exist?
>>>>>>>>>>>>>>>>>>>>
There is no such system on the 928
<<<<<<<<<<<<<<<<<<
My car whit ignition relè it had always run good except for the times when i
have hunting idle up and and resolved this defect by press the relè socket on the relè.Now the car with the relè inserted or bypassed run in the same way.Do you think that there's a possibility that the timing is gone bad?
>>>>>>>>>>>>>>>>>>>
The timing is set by a toothed gear on the engine, so timing cannot change. It is also most unlikely your valve timing has changed due to jumping a tooth.
<<<<<<<<<<<<<<<<<<<
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Thursday, August 21, 2008 10:50 AM
Subject: Re: possible MAF failure from Italy
For O2 test i have disconncted the O2 sensor plug and i have connected ltmeter to the single pin and ground at the top of the fuse panel.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
the O2 sesnor has to be plugged into the car to make a sensible measurement (so the loop is complete). You have to insert a wire into
the single pin socket to make a measurement weith the plug connected.
<<<<<<<<<<<<<<<<<
I don't find 12 way connector today i have removed the fuse and relè panel and i had find only connected plug not 12 way disconnected plug.I suppose that the 12 way plug wire originates from the LH plug cable.
It's correct?
>>>>>>>>>>>>>>>>>>
From the main LH/EZK cable form. The 12way plug has acover on it. It looks identical to the coding plug exccept it is longer.
<<<<<<<<<<<<<<<<<<<<
Yes my ignition relè it's connected but i don't have fitted it if you
remeber i said you that sometimes some months ago the car sometimes has idle hunting up and down and when i pressed the relè base on the ignition relè the idle returned normal. Yesterday i tried to bypass the relè i had connected A1-A2-87 but the engine run in the same way idle up and down Tonight i send you a photo of ignition relè wire.Do you think that there's a possibility that the car was converted with CAT when the car was in Germany.
>>>>>>>>>>>>>>>>
Maybe, but the car was running OK before ?
>>> <<<<<<<<<<<<<<<<<
There's a possibility that i have fitted the wrong type of coils (coils are
new) for model year 89 with CAT?
>>>>>>>>>>>>>>>>>>>>
PET says for MY 87 part 944 602 115 00 and from MY88 onwards 92860203900. But I don't know what the difference is.
Which side is the coil that you changed ? (as viewed sitting in driver's seat)
<<<<<<<<<<<<<<<<<
When i turn my ignition key i ear some click-click-click coming from the
engine i think on the left bank (cylinder 5-6-7-8) after 1 second the
click-click-click stop.
>>>>>>>>>>>>>>>>>>>>>>
??
John
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Wednesday, August 20, 2008 9:13 PM
Subject: Re: possible MAF failure from Italy
Hello
Your O2 sensor voltages are not correct, you meansured them with the
sensor still connected to the LH ECU ? See page 24-219 of the workshop
manual. In normal use the voltage with oscillate between 01.v and 800mV.
You are correct, your car is MY 88. It will have the 12way connector
that I described. It has probably been buried behind the LH/EZK ECUs.
If you have fitted the igntion protection relay (did you do this change?) then you should add the 150 ohm resistor, although this is only used when the relay is triggered.
See page 24-222 of the WSM. It is strange that only some plugs are
blacker than the others. You have the igntion protection relay in circuit
(i.e. not replaced with a bypass link ?
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Wednesday, August 20, 2008 7:53 PM
Subject: Re: possible MAF failure from Italy
I have measured the 02 sensor single pin and ground the value at the
idle was 0.01v and after with the engine at about 3000-4000 rpm the values have increased at 2.0v 3.0v after i have stopped the vaules test.
I don't undertstand because if i disconnect the O2 sensor and make battery reset nothing change the engine run in the same way.Today i have searched the diagnosis plug but I did not find anything my car first registration in 1987 vin number WPOZZZ92ZJS840062 and for this reason i assume that my car is model year 1988.My car have ignition monitoring sistem and the car is catalyzed but my coding plug don't have 150ohm resistance between pin 7 and pin 8 of the coding plug.In attached the spark plugs photos. (spark plug at cylinder 6-7-8 are more black)
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Wednesday, August 20, 2008 12:54 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
I certainly sounds as though the O2 loop is not in control at idle, and maybe also higher in the rpm/load range.....
You can meaure the O2 sensor voltage to see if the loop is working OK.It should move from about 0.2v to 0.9v quite quickly. If the voltage is high or low continuously, then maybe the O2 sensor is faulty. (Only measure O2 sensor volts when engine is at normal working temperature.)
If one injector is not flowing correctly, then there will be excess oxygen into the exhaust and the loop may be trying to obtain the correct CO at the sensor, this would give a rich mixture in the engine.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Wednesday, August 20, 2008 9:33 AM
Subject: Re: possible MAF failure from Italy
Yesterday i have make a gas tester on my car (I work in a Maserati workshop i'm a office man not a mechanic but i'm a fan of the vintage car i have got a maserati biturbo SI '87 and a mini de tomaso turbo '87) the CO is very high and the car is rich at the idle without black smoke on the tailpipe.Yesterday I had put in my gas tank one bottle of injector cleaner and the car goes a little better than before i have run for about 20 km and the engine does not cut out but my idle always hunting up and down yesterday i have checked the sparks plug after a little fast run around the workshop and the spark plugs returned clean. today i send you a photo of the spark plugs.There' is a possibility that my car have a rich situation only at the idle.Yesterday i returned at my home without the coding plug inserted and the car goes in the same way no difference but i don't remeber if i had make a battery reset when i have disconnected the coding plug.
My chief that is a Ferrari and Maserati mechanic suggested me to revise the
injectors
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Wednesday, August 20, 2008 9:59 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
No, the car will not run correctly without the 8 pin coding plug
inserted. The car will run very rich.
The diagnosis plug is a larger 12 way version of the coding plug. It
should be fixed to the same mounting plate that holds the LH and EZK ECUs
Sometimes they become detached from the plate, and can be out of
sight under or behind the plate.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Tuesday, August 19, 2008 10:19 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
I have one question for you.
The car can run without the 8 pin coding plug inserted?
Where is the diagnosis plug in my car?
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Tuesday, August 12, 2008 1:37 PM
subject: Re: possible MAF failure from Italy
OK Massimo, thanks for letting me know.
Good luck with your fault finding !
Regards
Jhon Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Tuesday, August 12, 2008 12:31 PM
Subject: Re: possible MAF failure from Italy
Hi.
Thank you John i have received the package today.
When i find a solution if you want we can write on rennlist.
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Tuesday, August 05, 2008 2:12 PM
Subject: Re: possible MAF failure from Italy
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Monday, August 04, 2008 8:52 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
It would improve throttle response somewhat. Max power will not be affected much because the S4 is fuelled rather on the rich side of nominal as standard.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Monday, August 04, 2008 7:32 PM
Subject: Re: possible MAF failure from Italy
Hi. John.
I have one question for you.
My MAF is 2,4 % aged if you had better calibrated it the engine would go better or not would be there any difference?
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Monday, August 04, 2008 4:54 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
Thank you for your Paypal. I posted your parts back to you today.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Sunday, August 03, 2008 1:33 PM
Subject: Re: possible MAF failure from Italy
Hi. John.
Are you 100% sure that my LH and EZK are good?
Now i can try to find my failure in others parts of my car?
My car have the ignition protection relay and if you remember i said you that when i had my drivers coil wire not well connected the car had started to run in four cylinder mode.But now there are not led illuminated on the protection ralay.Now my MAF is better calibrated than before?
My adress is:
MASSIMO CISTERNINO
VIA G.B. GRASSI, 2
30170 MESTRE-VENEZIA (VE)
ITALY.
I pay you with paypall.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Sunday, August 03, 2008 11:20 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
OK, MY 88, but all my comments below except the one ".......Does your car have the igntion protection relay ? With the red and green LEds ? I think so. Have you checked that these are not being illuminated ?..............." are applicable to your car.I have finished temperature testing your LH ECU, and I confirm that I have found no problems with any of your units
I am ready to send them back to you.
My charges are 90 Euro for testing, plus 18 Euro for the MAF
screen and locking ring. Postage and VAT will add 40 Euro.
Total is therefore 148 Euro. Can you pay by Paypal ? My Paypal
email address is info@jdsporsche.com
Please give me you return address for delviery.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Sunday, August 03, 2008 1:43 AM
Subject: Re: possible MAF failure from Italy
Hi.John.
My car is model year '88 but my car have ignition protection relay my coding plug have this code 92860743300 (WITHOUT RESISTANCE between pin 7 and pin 8 and without pin 8) this code is for rest of the world cars with manual transmission and catalityc converter on one of my manuals say that the car that have ignition protection relay must have coding plug 92860743800 with a resistance of 150 ohm between pin 7and pin 8.My manual say about ignition protection relay this:
Even with the undocking of a circuit injection four-cylinder aspire air, the probe lambda recognize a surplus of air and within the cylinder intact, adjusting an air / petrol towards enrichment. To avoid this,disconnecting a circuit ignition is turned off even the lambda probe.inserting the ignition contact 15 of the relay is tension through LH ECU. At the contact relay AL (this cable leads to contact 28 of LH ECU) with ignition on there is ground.The codification, with or without CAT for lh ECU runs through the positive or the mass contact 28 of lh ECU itself, with ignition on LH ECU is encoded by the AL contact relay for the service without CAT.If the engine is started to contact 61 of the relay there is the alternator tension thus there is tension at contact AL and thus the LH ECU is codified for the service with CAT.
If an ignition circuit fails and contact relay opens is given ground at contact AL and the LH ECU switches to service without CAT.But in cars without CAT the CO is regulated at the idle through a potentiometer, but this potentiometer is not available in cars with CAT (lambda self/auto regulating), with the ignition protection relay and thus lambda adjustment switching from the regulation with lambda probe to regulation without lambda probe , through a resistance of 150 ohm in the coding plug of the LH ECU is assigned a fixed value or a replacement value to the LH ECUt for ensure the functioning of the engine at the idle.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Saturday, August 02, 2008 12:56 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
I am in the middle of more tests on your LH. So far I have not found any problems.
When the car's water temperature is below about 70deg C, then the
O2 sensor is not used, the car runs open loop. So O2 sensor is
not a possible problem at that time. And not the reason for a very rich mixture.
Does your car have the igntion protection relay ? With the red and green LEds ? I think so. Have you checked that these are not being illuminated ?
Are you quite sure the spark plug leads are on the correct cylinders ?Have you checked fuel pressure ? Also check fuel flow rate, at the return to the tank at the rear (there is a test in the workshop manual).
Also make sure that there is no fuel in the vacuum lines to the fuel pressure regulator, or the two fuel dampers. Sometimes the diaphram in them can split and fuel gets into the engine vacuum lines.
I see you have been measuring for vacuum leaks - good.
Have you measured battery volts with engine ruuning ?
Check carefully that the coding plug conatcts are OK. This is
the 8 way plug/socket on the LH/EZK mounting plate.Pin 1 is ground (chassis). Pins 2,4 & 7 are also linked to ground via pin 1.
Make sure all ground points are a good connection - less than
1 ohm from LH and EZK 35way plugs.
I will have finished testing today.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Saturday, August 02, 2008 12:21 AM
Subject: Re: possible MAF failure from Italy
Ok John.but the defect start to manifest it when i start the car with rich mixture with strong smell of fuel (my eyes burning) and with small accelerator openings the engine hesitate and after go down with a low idle and after return at the idle.
When the engine is heating the idle start surging up and down and after when for example i go out for a tour around my garage the engine die at the stop. I think that could be a multiple failure O2 sensor plus ignition modules or plus an air leak (i have found one air leak under the intake think betwen the spider and the throttle body on the top) or plus alternator or plus fuel pump or fuel filter or check valve (fuel filter and check valve are new about 4000 km but there is a possibility that i have clogged it when i went out for a tour and my fuel tank was empty) or i don't know???????????????????
what do you think about my problem if MAF (have you calibratedit?) is ok my LH is ok and my EZK is ok???????????????
Regards.
Massimo.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Friday, August 01, 2008 11:18 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
No, I haven't found anything. I was hoping to test more today, but I just didn't have time. I will be doing more test tommorrow. I always seem to be working at weekends :-)
I am going to concentrate on your LH ECU. I will temperature test it just to make sure there isn't an obscure fault that is not obvious normally. I will use the "SharkTuner" to do these tests, as it tells me exactly what is going on inside the ECU.
By the end of the weekend I will be able to tell you if there
is anything wrong with your units.....
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Friday, August 01, 2008 7:37 PM
Subject: Re: possible MAF failure from Italy
Hi.John.
Have you got any news for me? Have you find some defect?
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Friday, August 01, 2008 10:31 AM
Subject: Re: possible MAF failure from Italy
Ah ! OK :-)
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: "massimo" <maxerati@libero.it>
To: "JDSPorsche" <info@jdsporsche.com>
Sent: Thursday, July 31, 2008 8:36 PM
Subject: Re: possible MAF failure from Italy
Venice is very beautiful it is a unique city.
If you come again to Venice you can take a hotel in Mestre to pend less. I ive in Mestre-Venezia.
----- Original Message -----
From: "JDSPorsche" <info@jdsporsche.com>
To: "massimo" <maxerati@libero.it>
Sent: Thursday, July 31, 2008 7:48 PM
Subject: Re: possible MAF failure from Italy
OK, thanks for that info. I will do more testing later today and tommorrow. My wife and daughter were in Venice earlier this year. They still talk about it :-)
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 6:13 PM
Subject: Re: possible MAF failure from Italy
I have checked the resistance at the lh and ezk 35way plugs and was in the normal range i have also checked the sensor in a cup of hot water and the values are normal at 80 c° 60 c° and ecc....... The problem of my car are rich running immediately when the car is cold with black spark and a lot of condensation water in my exhaust my idle surging up and down and my car cut out when it is hot and when cut out the rev counter not drop instantly my idle go down with warning light on and my car cut out. when the car is very hot it is hard to start if i start without gas pedal pressed my car start and after immediately cut outs.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, July 31, 2008 5:37 PM
Subject: Re: possible MAF failure from Italy
Hello Massimo,
I can supply new screens and lock rings. The price for both (new) would be 18 Euro plus VAT.I am wondering if the problem with your car is linked to the work you did with Temp 2 sensor ? Have you check the temp 2 resistances
at the LH and EZK disconnected 35way plugs ?
I will do some more tests on your LH and EZK later
today.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 12:57 PM
Subject: Re: possible MAF failure from Italy
Ok John.
Have you got used parts or you must order it at porsche code 92811090100 and 92811090200 ?
If my MAF my LH and my EZK are good.
What may be the fault?
Did I already told the work I was doing (replaced radiator expansion tank with new cap,connector of temp II sensor new coils with updated coil cable my car in origin mount first type of coil with old type of cable) on my car before they manifest failure.It happened that one day to prove my car I think I have remained almost without gasoline because my car was not good if the accelerator was full depressed after I made gasoline the car was going as before.Few months ago I have started another car with cables attached on my 928.A lot of few months ago the idle surging up and down and the problem is resolved if I touched the base of the ignition monitoring
system relè.Have you got any idea ?
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, July 31, 2008 11:54 AM
Subject: Re: possible MAF failure from Italy
The screens do help to create a laminar airflow over the MAF sensor heated wire. Some people do remove the lower screen thinking it"improves
airflow" but this is not a good idea.I have never heard for removing the screen causing the
issues you have (rich running) but I think you should have that screen
in place.
I can supply and fit.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 10:15 AM
Subject: Re: possible MAF failure from Italy
i don't know i have removed the MAF and i have find
only the top screen.
---- Original Message -----
From: JDSPorsche
To: massimo
Sent: Thursday, July 31, 2008 11:09 AM
Subject: Re: possible MAF failure from Italy
I have one question - why has the bottom screen
been removed
from your MAF ?
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Thursday, July 31, 2008 9:46 AM
Subject: Re: possible MAF failure from Italy
Hi.John.
Have you received my package?
Regards.
Massimo.
--- Original Message -----
From: JDSPorsche
To: massimo
Sent: Tuesday, July 29, 2008 9:52 PM
Subject: Re: possible MAF failure from Italy
Ok thanks for letting me know !
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, July 29, 2008 8:35 PM
Subject: Re: possible MAF failure from Italy
Hi.
You should receive the package tomorrow.
Regards.
Massimo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Monday, July 28, 2008 4:50 PM
Subject: Re: possible MAF failure from Italy
OK Massimo,
I willl et you know as soon as they
arrive here.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Monday, July 28, 2008 3:21 PM
Subject: Re: possible MAF failure from Italy
Hi.
I have decided to send you for a test
the EZK ecu also.
Regards.
Massimo.
I think that the package arrive to you
about Wednesday or Thursday.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Sunday, July 27, 2008 12:01 AM
Subject: Re: possible MAF failure from Italy
Hello Massimo
OK, I will let you know as soon as I receive your parts, and what I find with testing them.
Regards
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Saturday, July 26, 2008 8:17 PM
Subject: Re: possible MAF failure from Italy
Hi.
Next week i want ship you my MAF and my LH ECU.Please give me confirmation.
Regards.
Massimo
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Tuesday, July 15, 2008 11:13 PM
Subject: Re: possible MAF failure from Italy
Unless you have a severe misfire caused by faulty output stages etc, which would allow unburnt fuel into
the exhaust,then no, I doubt this is the problem with your car.
It does sound as though, for some reason, the O2 loop is not working as it should......
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, July 15, 2008
9:49
PM
Subject: Re: possible MAF
failure
from Italy
the ignition trigger or the ignition final output stages.see the photo.
----- Original Message -----
From: JDSPorsche
To: massimo
Sent: Tuesday, July 15, 2008
10:38 PM
Subject: Re: possible MAF
failure from Italy
I don't know quite what you mean by "output stages" - please explain...
John Speake
www.jdsporsche.com
+44 (0)1223 709915
----- Original Message -----
From: massimo
To: JDSPorsche
Sent: Tuesday, July 15, 2008
7:57 PM
Subject: Re: possible MAF
failure from Italy
OK this help me. thank you.and the final output stages?
wich the typical sign of fault in this component and if you know the
non typical?
----- Original Message -----
From: JDSPorsche To: massimo
Sent: Tuesday, July 15, 2008 7:33 PM
Subject: Re: possible MAF failure from Italy
I have tested the full load contact and the ohm value is about 20 ohm ( the workshop say that the value must be minor of 10 ohm) and also say: " if the full load contact fail the control unit geberates a load threshold by way of the air mass sensor. Values below this load are the same as if the switch were open,values above it are the same as if the switch were closed.What does mean this?
Hi
It means that if the full load switch fails,the LH ECU can still recognise a high engine load (i.e. throttler well open) and hence provides the enrichment required. It won't be as precise as if the LH ECU also received the full load switch input as well.....the ohm value that i have tested were initially minor and after that i have pressed the gas pedal few times the value increased.There are known problems with the throttle switches. Solder joints inside can fail, and then the full load switch can even go open circuit at all times. What do you think about a possibile fault
output stages or alternator a fault on this component can make rich mixture?.
The LH ECU monitors battery voltage and if it is below the normal voltage increases the injector opening times in order to compensate for the extra time the injectors take to open with a low voltage. Conversely, as battery volts rise, the injector on times are reduced.Normal opening time to open an injector is about 1mS. This time is added to the actual time the injector is required to delvier fuel when fully open.So you will only get unwated enrichment if the LH ECU sees a low battery voltage, or has a fault that makes it think a normal voltage is lower than it actually is.
Hope this helps ?
Regards John
----- Original Message ---
From: massimo
To: JDSPorsche
Sent: Tuesday, August 19, 2008 1:24 PM
Subject: Re: possible MAF failure from Italy
Hi.I have tested the temperature sensor II in a cup of hot water with a termocouple attached on it and the ohm values are normal.I have also tested the engine temperature sensor II with plug inserted and the values are different like if there are some resistance in parallel the value with the ezk and lh ecu plug detached are normal.The value of temperature sensorII are the
same with plug inserted and with plug not inserted?I have cleaned all spark plugs.
11-27-2008, 07:40 PM
#2
Nordschleife Master
To sum this up for everyone so that you get more responces.
John Speake has tested the MAF, LH, and EZK all are in known good condition.
Car runs extremely rich, and surges at idle.
Injectors have checked out ok.
TempII sensor checks out OK.
If MAF unplugged car will not run.
O2 sensor has no change if disconnected.
Car runs much better if unmetered air is allowed into the manifold.
Looking for information as to what the correct coding plug he should be using, he has an 88 ROW car with Ign monitering system and believes he should have 150ohms between pin 7 and 8 of coding plug
John Speake has tested the MAF, LH, and EZK all are in known good condition.
Car runs extremely rich, and surges at idle.
Injectors have checked out ok.
TempII sensor checks out OK.
If MAF unplugged car will not run.
O2 sensor has no change if disconnected.
Car runs much better if unmetered air is allowed into the manifold.
Looking for information as to what the correct coding plug he should be using, he has an 88 ROW car with Ign monitering system and believes he should have 150ohms between pin 7 and 8 of coding plug
11-27-2008, 07:44 PM
#3
Nordschleife Master
My suggestions on this is #1 as John has already suggested but I did not see a responce. Possible I missed it as it is a difficult read. Remove the vacuum lines from the fuel pressure regulator and fuel dampners. I believe that the diaphram is split in one of them. Once the lines are removed jumper the fuel pump relay and check for fuel leaks on the vacuum ports of the FRP and dampners.
#2 I would also replace all ign leads, caps and rotors. If the fuel goes into the engine and is not ignited then straight oxygen will be read by the sensor telling the brain to dump MORE fuel into the engine.
I would also recommend that you do as John recommends and check the fuel pressure against the specs in the work shop manual.
#2 I would also replace all ign leads, caps and rotors. If the fuel goes into the engine and is not ignited then straight oxygen will be read by the sensor telling the brain to dump MORE fuel into the engine.
I would also recommend that you do as John recommends and check the fuel pressure against the specs in the work shop manual.
11-27-2008, 08:51 PM
#4
Race Director
I was just randomly cruising the 928 board and I had a very similar problem on my 87 944 Turbo. I know it is a different car, but my problem ended up being the harness for the temp sensor and a faulty DME. Also check injector spray pattern, fuel pressure, and plug a noid light into each injector clip and crank. Wouldn't hurt to pressure check the intake system.
Also, did anyone work with the intake, idle control, or idle screw?
Also, did anyone work with the intake, idle control, or idle screw?
11-27-2008, 10:31 PM
#5
Nordschleife Master
Mike, The temp sendor and plug have been checked, the DME equal on this has been checked, injectors have been checked, the idle control is all electric and nothing to adjust, as well if there was a vacuum leak it would cause a lean condition with a higher idle. The injectors are all firing, though too well it seems.
Trending Topics
11-28-2008, 05:04 PM
#10
Advanced
Thread Starter
Join Date: Apr 2007
Location: Italy Mestre-Venice
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
i have replaced the ignition coils also.
i don't have the 150ohm resistor between pin 7 and 8 of coding plug.
If you read precedent message with John i think that the car was upgraded time ago with ingition monitoring system and ezk and lh full diagnosis version but i don't have 19 pin diagnosis plug.
i don't have the 150ohm resistor between pin 7 and 8 of coding plug.
If you read precedent message with John i think that the car was upgraded time ago with ingition monitoring system and ezk and lh full diagnosis version but i don't have 19 pin diagnosis plug.
11-29-2008, 12:34 AM
#13
Nordschleife Master
That is a good call Mike on using the vacuum pump, I have never smelt or felt fuel on those lines unless they had failed.
As well the one thing that has not been answered is have you checked the fuel pressure, running and not?
As well the one thing that has not been answered is have you checked the fuel pressure, running and not?