Help With Distributor Sensor Plug
#16
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Dear Blue,
Firstly my book does not contain wiring diagrams. It is a book and not an actual manual and the wiring diagrams fill an entire volume from PAG. Thereis plenty of stuff in thebook but the inconnect diagrams are not part of it.
Now we need to get a couple of things sorted. You own a 1990 C2 Targa. This is very important when asking for information. Please confirm it is RHD.
Now I need a couple of questions answered.
1/. What fuel are you using. Octane?
2/. Please look at the label on the underside of the luggage comparmtent lid and post all the option numbers. The option line should start C16 then a whole bunch of 3 digit numbers.
If you do not have an O2 sensor then you have a problem. Your si not a standard 964 and it must be a M150 version. If it is a M150 version this is designed to run on leaded fuel. Instead of O2 sensor these were fitted with altitude compensators.
You need to run on high octane fule if this is all correct. Using a Bosch Hammer on these puppies is also a waste of time.
However we are ahead of ourselves. Please answer the questions asked first.
Ciao,
Adrian
964C4
Firstly my book does not contain wiring diagrams. It is a book and not an actual manual and the wiring diagrams fill an entire volume from PAG. Thereis plenty of stuff in thebook but the inconnect diagrams are not part of it.
Now we need to get a couple of things sorted. You own a 1990 C2 Targa. This is very important when asking for information. Please confirm it is RHD.
Now I need a couple of questions answered.
1/. What fuel are you using. Octane?
2/. Please look at the label on the underside of the luggage comparmtent lid and post all the option numbers. The option line should start C16 then a whole bunch of 3 digit numbers.
If you do not have an O2 sensor then you have a problem. Your si not a standard 964 and it must be a M150 version. If it is a M150 version this is designed to run on leaded fuel. Instead of O2 sensor these were fitted with altitude compensators.
You need to run on high octane fule if this is all correct. Using a Bosch Hammer on these puppies is also a waste of time.
However we are ahead of ourselves. Please answer the questions asked first.
Ciao,
Adrian
964C4
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Dear Jon,
We need to know the mod status of the 964 first. No O2 sensor means non standard configuration. No point trying to troubleshoot when you do not know exactly what you are trying to troubleshoot.
Ciao,
Adrian
964C4
We need to know the mod status of the 964 first. No O2 sensor means non standard configuration. No point trying to troubleshoot when you do not know exactly what you are trying to troubleshoot.
Ciao,
Adrian
964C4
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Hi Adrian.
Thanks for your reply. The information on my car is as follows:
The car is RHD.
I use 95 RON fuel as a sticker inside the fuel flap says to do so.
There is a Bosch altitude compensator fitted under the passenger seat near the DME unit.
Option line reads C26 150 330 383 387
Paint / Interior 425 567 573
Options 10011
Also the following may be of use
ECU Number 0 261 200 182
Chassis No WP0ZZZ96ZLS410076
Does the 150 in the options line mean I need to use 98 RON and have I bought an odd ball?
Is it possible to de-code the options from the numbers?
The head temp sensor checks out ok from cold right through to opperating temperature on both the resistance readings kindly supplied by Adrian previously, and also on the Bosch diagnostic tool. So I'm assuming the ECU knows the engine temperature correctly for now.
Regards
Blue
Thanks for your reply. The information on my car is as follows:
The car is RHD.
I use 95 RON fuel as a sticker inside the fuel flap says to do so.
There is a Bosch altitude compensator fitted under the passenger seat near the DME unit.
Option line reads C26 150 330 383 387
Paint / Interior 425 567 573
Options 10011
Also the following may be of use
ECU Number 0 261 200 182
Chassis No WP0ZZZ96ZLS410076
Does the 150 in the options line mean I need to use 98 RON and have I bought an odd ball?
Is it possible to de-code the options from the numbers?
The head temp sensor checks out ok from cold right through to opperating temperature on both the resistance readings kindly supplied by Adrian previously, and also on the Bosch diagnostic tool. So I'm assuming the ECU knows the engine temperature correctly for now.
Regards
Blue
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Hi Adrian.
The Porsche number on the DME is as follows:
911.618.124.02
TYP 911 MW-DZ-01.
Just today I removed the new air flow sensor that the local Bosch agent fitted last week. Just out of interest I checked how far the adjustment screw was set as I watched the mechanic use it to set the CO reading to 2.3% and heard the idle quality improve. The screw is fully down ie fully rich. I am now thinking that maybe I have an air leak in the intake system. I do know that removing one of the small vacuum hoses after the engine is stopped for some time I get a hiss showing that these lines at least are sealed but I guess I could still have a leak on the rest of the system.
Enjoy your Scottish trip. It is really beautiful up there at this time of year.
Regards
Blue
The Porsche number on the DME is as follows:
911.618.124.02
TYP 911 MW-DZ-01.
Just today I removed the new air flow sensor that the local Bosch agent fitted last week. Just out of interest I checked how far the adjustment screw was set as I watched the mechanic use it to set the CO reading to 2.3% and heard the idle quality improve. The screw is fully down ie fully rich. I am now thinking that maybe I have an air leak in the intake system. I do know that removing one of the small vacuum hoses after the engine is stopped for some time I get a hiss showing that these lines at least are sealed but I guess I could still have a leak on the rest of the system.
Enjoy your Scottish trip. It is really beautiful up there at this time of year.
Regards
Blue
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Dear Blue,
You have already shown me that your 964 was destined for South Africa and is a confirmed option M150 engine which means higher compression and designed to run on leaded fuel. The first thing you have to do is to convert to 98 Octane Super Plus unleaded fuel. With 95 octane fuel you are going to have running problems pinging etc. I have no idea why you have a 95 Octane label on the fuel cap.
There are many other differences between your engine and a standard version so I cannot determine anything about the manual adjustment of the CO2.
What I can tell you is that your engine does not have open loop and closed loop operation. The altitude compensation device does exactly that compensates for reduce air density. How the rest of this system works is a mystery. Yours is the first normally aspirated M150 I know of. The Turbos I know of especially in the middle east but not C2s and C4s.
Ciao,
Adrian
964C4
You have already shown me that your 964 was destined for South Africa and is a confirmed option M150 engine which means higher compression and designed to run on leaded fuel. The first thing you have to do is to convert to 98 Octane Super Plus unleaded fuel. With 95 octane fuel you are going to have running problems pinging etc. I have no idea why you have a 95 Octane label on the fuel cap.
There are many other differences between your engine and a standard version so I cannot determine anything about the manual adjustment of the CO2.
What I can tell you is that your engine does not have open loop and closed loop operation. The altitude compensation device does exactly that compensates for reduce air density. How the rest of this system works is a mystery. Yours is the first normally aspirated M150 I know of. The Turbos I know of especially in the middle east but not C2s and C4s.
Ciao,
Adrian
964C4
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Looks like I’ve found the culprit the starting and rough running when cold problem (Kangarooing) that I’ve had since I bought my M150 spec C2 Targa and it was not an air leak!
I spent some time on Saturday with a Fluke meter, some lengths of wire and the connector pin diagram of the DME control unit from the 964 manual and buzzed through all the lines from engine to the 55 way connector. All wiring runs were good and remained good when I shook as much of the loom as I could get to, except the air flow sensor line going to pin 7, the speed signal wire to pin 47 and the main battery supply to pin 18. These were wired via an after market immobiliser, fitted long before I bought the car. First problem with this is that the DME will be re-set every time the car is left switched off for more than a few minutes. Now I’m not sure if the DME “remembers” adaptive idle strategy or not but a permanent 12V supply should be just that and in my cars case was not. I guess this would also explain why the Bosch agent (who, incidentally has not charged me as he could not find the fault) could never get any historical faults logged in the DME with the diagnostic tool.
With the immobiliser key in place I noticed that the airflow sensor connection did not always make very good contact and the line resistance varied. This may explain the need for the fully in adjustment on the air flow meter to achieve a reasonable CO value at idle.
I bypassed all the DME related immobiliser circuits and tidied all the wiring in the back of the DME 55 way plug that the immobiliser installer had messed up. Net cost, some solder and a few short lengths of heat shrink. The car has started first time and driven perfectly for 3 out of 3 cold starts now, so I believe I have a fix. Not a quick fix but very satisfying all the same.
The immobiliser still works on other circuits so it will still take a concerted effort to start the car without the relevant key.
I was so pleased with my fix that I treated the car to a wash, new bonnet struts, trunk lid internal light fix and some glued heat shrink on the Targa clips to stop the annoying rattles over bumps. It’s like driving a different car!
Many thanks for all the advice especially the section of wiring diagram from Taj. This is a great discussion group!
If you are suffering similar seemingly unfathomable issues with the running of your 964 all I can suggest is start simple, do not throw money at the problem unless you have no alternative and above all keep at it, you’ll be surprised how much you learn!
Right next project on the list, I need some 17” Cup 1 wheels and tyres, new rear Targa seal, the carpets could do with a freshen up, a Cup pipe, then there are those stone chips…….Oh and a garage that needs building.
Blue C2
I spent some time on Saturday with a Fluke meter, some lengths of wire and the connector pin diagram of the DME control unit from the 964 manual and buzzed through all the lines from engine to the 55 way connector. All wiring runs were good and remained good when I shook as much of the loom as I could get to, except the air flow sensor line going to pin 7, the speed signal wire to pin 47 and the main battery supply to pin 18. These were wired via an after market immobiliser, fitted long before I bought the car. First problem with this is that the DME will be re-set every time the car is left switched off for more than a few minutes. Now I’m not sure if the DME “remembers” adaptive idle strategy or not but a permanent 12V supply should be just that and in my cars case was not. I guess this would also explain why the Bosch agent (who, incidentally has not charged me as he could not find the fault) could never get any historical faults logged in the DME with the diagnostic tool.
With the immobiliser key in place I noticed that the airflow sensor connection did not always make very good contact and the line resistance varied. This may explain the need for the fully in adjustment on the air flow meter to achieve a reasonable CO value at idle.
I bypassed all the DME related immobiliser circuits and tidied all the wiring in the back of the DME 55 way plug that the immobiliser installer had messed up. Net cost, some solder and a few short lengths of heat shrink. The car has started first time and driven perfectly for 3 out of 3 cold starts now, so I believe I have a fix. Not a quick fix but very satisfying all the same.
The immobiliser still works on other circuits so it will still take a concerted effort to start the car without the relevant key.
I was so pleased with my fix that I treated the car to a wash, new bonnet struts, trunk lid internal light fix and some glued heat shrink on the Targa clips to stop the annoying rattles over bumps. It’s like driving a different car!
Many thanks for all the advice especially the section of wiring diagram from Taj. This is a great discussion group!
If you are suffering similar seemingly unfathomable issues with the running of your 964 all I can suggest is start simple, do not throw money at the problem unless you have no alternative and above all keep at it, you’ll be surprised how much you learn!
Right next project on the list, I need some 17” Cup 1 wheels and tyres, new rear Targa seal, the carpets could do with a freshen up, a Cup pipe, then there are those stone chips…….Oh and a garage that needs building.
Blue C2
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At work we do have advanced meters which can log data and display waveforms etc (not cheap though) but I was using a basic one for the work I did. I've got my own cheap and nasty meter but the Fluke is more robust, easier to use and has better accuracy displaying resistance values.
Have a look here.
http://www.fluke.com/
Blue C2
Have a look here.
http://www.fluke.com/
Blue C2