993 tiptronic won't start after 2 years put away in garage
05-12-2013, 04:05 AM
#61
Instructor
Join Date: Apr 2007
Location: Taiwan
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Hello
thanks all for the feedback....
... about the connection of a new battery and locking doors ... this thing I knew ... I do have a 964 which did the same thing...
But back to the 993:
Worked quite late yesterday evening at the 993
So I installed a working ignition module (under the seat)
Then I got 12V on both coils so this was good
Also at the hall sensor I had 5V
But still no spark at the cables .... :-(
So my guess was only the dual ditributor can only be bad?
There is a module located at the hall sensor plug
So I installed a new dual dstributor on the car..... damn those things get stuck.... took me almost 2h to remove this one..
I got stuck by the black O-ring
Anyhow changed it with a new one started the car.... and yes it starts again BUT still terrible (seems to run only at 6 cylinders) and stalls very fast ... ± 10 seconds
Still can't get the engine at high rpm levels and at this low rpm its very irregular.
Also the car smokes a little and it's getting way to much petrol (my opinion)
Then took a old sparkplug and installed it IMMIDIATTELY in the cable that goes to the right coil (so connection is: Coil-cable- spark)... here I have a strong spark
Then did the same thing with the left coil ... and NO spark??
So from the ignition system is now changed:
-2 distributor caps
-2 rotors
-ignition module (under the driver seat)
-Dual distributor
-Second hand coil set
Could it be that the crankcase speed sensor is corrupt?
Is it possible to check the sensors that are on the engine (speedsensor, cold cylinder sensor,..) with an ohm meter to verify if these still are ok?
Any feedback is welcome
thanks all for the feedback....
... about the connection of a new battery and locking doors ... this thing I knew ... I do have a 964 which did the same thing...
But back to the 993:
Worked quite late yesterday evening at the 993
So I installed a working ignition module (under the seat)
Then I got 12V on both coils so this was good
Also at the hall sensor I had 5V
But still no spark at the cables .... :-(
So my guess was only the dual ditributor can only be bad?
There is a module located at the hall sensor plug
So I installed a new dual dstributor on the car..... damn those things get stuck.... took me almost 2h to remove this one..
I got stuck by the black O-ring
Anyhow changed it with a new one started the car.... and yes it starts again BUT still terrible (seems to run only at 6 cylinders) and stalls very fast ... ± 10 seconds
Still can't get the engine at high rpm levels and at this low rpm its very irregular.
Also the car smokes a little and it's getting way to much petrol (my opinion)
Then took a old sparkplug and installed it IMMIDIATTELY in the cable that goes to the right coil (so connection is: Coil-cable- spark)... here I have a strong spark
Then did the same thing with the left coil ... and NO spark??
So from the ignition system is now changed:
-2 distributor caps
-2 rotors
-ignition module (under the driver seat)
-Dual distributor
-Second hand coil set
Could it be that the crankcase speed sensor is corrupt?
Is it possible to check the sensors that are on the engine (speedsensor, cold cylinder sensor,..) with an ohm meter to verify if these still are ok?
Any feedback is welcome
05-12-2013, 04:26 AM
#62
Hello TCtung
That was also my next guess:
"Could it be that the crankcase speed sensor is corrupt?"
"Is it possible to check the sensors that are on the engine "
If somebody knows the ohm values between the 3 pins of this sensor I can tell if this one still is ok
That was also my next guess:
"Could it be that the crankcase speed sensor is corrupt?"
"Is it possible to check the sensors that are on the engine "
If somebody knows the ohm values between the 3 pins of this sensor I can tell if this one still is ok
05-12-2013, 06:35 AM
#63
Rennlist Member
try after unplugging hall sensor if there is spark from second distributor
05-12-2013, 08:57 AM
#65
Drifting
Just saw this thread. Your problems suck, that is for sure. The one thing that I noticed is that you keep saying that Distibutor 2 has no spark so I will ask the obvious - is the belt still in one piece in the distributor? Did not see anyone ask this but I would guess you did since you said you own a 964.
Where are you located? If near StL MO I have a spare ignition module and distributor you could pop in and see if it makes a difference rather than spending money *****-nilly.
Where are you located? If near StL MO I have a spare ignition module and distributor you could pop in and see if it makes a difference rather than spending money *****-nilly.
05-12-2013, 01:38 PM
#67
Instructor
So you're getting no spark from from the left distributor and left coil. Try that same test but swap the left and right coil leads. ie: Run distributor 2 off of rightmost coil. And distributor 1 off of leftmost coil. Then report back where you're getting spark.
Also I'm pretty sure the car should be able to run off one coil. You're saying yours is running rough then stalls in 10 seconds. You're either getting weak spark or bad timing. You've ruled out a fuel problem. As far as I know, the crankshaft reference sensor is a all or nothing thing. If it doesn't work or isn't gapped correctly, the car will not start at all. One other sensor you should check is your CHT sensor. That could be causing similar symptoms, such as running rich.
Also I'm pretty sure the car should be able to run off one coil. You're saying yours is running rough then stalls in 10 seconds. You're either getting weak spark or bad timing. You've ruled out a fuel problem. As far as I know, the crankshaft reference sensor is a all or nothing thing. If it doesn't work or isn't gapped correctly, the car will not start at all. One other sensor you should check is your CHT sensor. That could be causing similar symptoms, such as running rich.
05-12-2013, 02:46 PM
#68
Ok BeauBlues
i will check this swap with cables on the coils tomorrow.
About the cold temperature sensor.... well do you or anyone else here on the forum knows the values (ohm) between the pins on this sensor?
That way I would like to measure all the sensors (in the left tree hanging)
i will check this swap with cables on the coils tomorrow.
About the cold temperature sensor.... well do you or anyone else here on the forum knows the values (ohm) between the pins on this sensor?
That way I would like to measure all the sensors (in the left tree hanging)
05-12-2013, 03:06 PM
#69
I'm throwing this out there in case it hasn't been mentioned before. During extended storage of any vehicle there's always a chance of mice having infiltrated cockpit, engine bay, wiring and electronics, these little rodents love to eat wire insulation and may have compromised the wiring system. Have you checked all the wiring for signs of being nibbled on or compromised?
05-12-2013, 03:20 PM
#70
BB, I don't believe your "all or nothing" statement about the reference sensor is correct. My car had an intermittent no start condition over a period of three or four years. If I "bumped" the starter (didn't hold it long enough for the engine to start) the car would crank but not start until after it sat for several minutes. My indie measured voltage output from the reference sensor. Although it was below spec, sometimes it was adequate to start the car. At other times (e.g., after bumping the starter), the output was considerably less and the car would crank but not start.
05-12-2013, 03:38 PM
#71
Instructor
A quick google search turned up this...
The Bentley "Porsche 964 Without Guesswork" book says the cylinder head temp sensors resistance varies between 32 degrees 4.4k-6.8k, 60-85 degrees 1.4k-3.6k, 105 degrees 1.0k-1.3k, 175 degrees 0.250k-0.390k, 265 degrees 0.090k.
The Bentley "Porsche 964 Without Guesswork" book says the cylinder head temp sensors resistance varies between 32 degrees 4.4k-6.8k, 60-85 degrees 1.4k-3.6k, 105 degrees 1.0k-1.3k, 175 degrees 0.250k-0.390k, 265 degrees 0.090k.
05-12-2013, 03:41 PM
#72
Just checked the resistance values on all 3 sensors, located at the sensor "tree":
Crankshaft speed sensor - BLACK socket
Between pin 1-2: 0.52kohm
Between pin 2-3:OL ??
Between pin 1-3: OL??
Cylinder temp sensor - WHITE socket
Between pin 1-2: 3.34kohm
Knock sensor - GREEN socket
Between pin 1-2: OL
Between pin 2-3:OL
Between pin 1-3:OL
I'm not so happy with these measurements because I have to much "OL"
and if I interpretate it correct the left knock sensor has an open contact so this should be replaced? BUT can this explain my problem with the engine?
Crankshaft speed sensor - BLACK socket
Between pin 1-2: 0.52kohm
Between pin 2-3:OL ??
Between pin 1-3: OL??
Cylinder temp sensor - WHITE socket
Between pin 1-2: 3.34kohm
Knock sensor - GREEN socket
Between pin 1-2: OL
Between pin 2-3:OL
Between pin 1-3:OL
I'm not so happy with these measurements because I have to much "OL"
and if I interpretate it correct the left knock sensor has an open contact so this should be replaced? BUT can this explain my problem with the engine?
05-13-2013, 09:14 AM
#74
Rennlist Member
There is one thing I need you to do.
Remove the air blower on the top left of engine, and locate the left injection rail.
Above cylinder number three (3), there is a pressure regulator on the fuel rail, with a vacuum hose coming out.
Put contact on or bridge the relay so that the fuel pump humms for 10-15 seconds.
Put contact off.
Go to the pressure regulator, and remove the small black vacuum tube.
Is there gasoline in the tube ?
As for electricity, you have to swap coils to see if you have spark on the secondary distributor.
Remove the air blower on the top left of engine, and locate the left injection rail.
Above cylinder number three (3), there is a pressure regulator on the fuel rail, with a vacuum hose coming out.
Put contact on or bridge the relay so that the fuel pump humms for 10-15 seconds.
Put contact off.
Go to the pressure regulator, and remove the small black vacuum tube.
Is there gasoline in the tube ?
As for electricity, you have to swap coils to see if you have spark on the secondary distributor.
05-13-2013, 05:32 PM
#75
Hello Geolab
Shortened the DME relais and fuel pump run for 15 seconds.
Removed the vacuumhose... but this is dry.... while running the fuel pump I can hear a "sissing" sound on the regulator.
Swapped the coils and now I have Sparks on the other distributor
Shortened the DME relais and fuel pump run for 15 seconds.
Removed the vacuumhose... but this is dry.... while running the fuel pump I can hear a "sissing" sound on the regulator.
Swapped the coils and now I have Sparks on the other distributor