83 928S Won't Start
04-25-2009, 07:25 PM
#31
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Well, I just finished removing the harness and taking it apart to inspect the damage. Every single wire in the section that goes from the T14 connector to the alternator and starter was completely destroyed. What a mess. I've just dumped out two big boxes of wiring harnesses rescued from salvaged VW/Audi vehicles. Let the recreation begin! Oh yipee.
04-25-2009, 07:37 PM
#32
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Well, this will definitely help you. Its great that you found this stuff. You sound like you have a lot of automotive experience.
Be aware of the sharpness of the body where the front harness runs near the radiator. It can cut the wires.
There are grounds to clean in this area at the very front of the car, one to the left (passenger side) of the radiator and one to the right of it.
Have you removed your fuse box and cleaned it yet? If not, after you repair the critical stuff noted, don't wait too long to do this. My wife and I pulled an 86 fusebox this morning, cleaned it, and replace it by early afternoon. Replaced all fuses. Dremel wire brushes are good for this job.
The fan and inlet air box is just above the fusebox. Its sealed with tar adhesive strips. it leaks and the water corrodes the fusebox. The housing has a single HVAC diaphragm also, that you need to replace when you go into it. ( I got my car mechanically right, cleaned the fusebox, then did this job a year later). While in there, you need to squirt oil on the fan shaft. Rog100 can supply the diagphram.
Be aware of the sharpness of the body where the front harness runs near the radiator. It can cut the wires.
There are grounds to clean in this area at the very front of the car, one to the left (passenger side) of the radiator and one to the right of it.
Have you removed your fuse box and cleaned it yet? If not, after you repair the critical stuff noted, don't wait too long to do this. My wife and I pulled an 86 fusebox this morning, cleaned it, and replace it by early afternoon. Replaced all fuses. Dremel wire brushes are good for this job.
The fan and inlet air box is just above the fusebox. Its sealed with tar adhesive strips. it leaks and the water corrodes the fusebox. The housing has a single HVAC diaphragm also, that you need to replace when you go into it. ( I got my car mechanically right, cleaned the fusebox, then did this job a year later). While in there, you need to squirt oil on the fan shaft. Rog100 can supply the diagphram.
04-25-2009, 07:44 PM
#33
Burning Brakes
if you haven't had the car running for a few months or more my guess would be sticking injectors. Additives in the gas become laquer when the fuel has evaporated.
Can you hear the injectors clicking when you turn the engine over ?
If not disconnect all the injector electrical connectors and flash 12v across each injector in turn 10 -15 times to free up the injectors.
Each time you brush 12v over the injector terminal You should hear a clear and distinct click as the internal solenoid plunger hits one end of the injector then another click when it returns as the power is removed.
IMPORTANT do not apply 12volts to the injector for a sustained period even seconds could damage the injector. The technique is to apply the 0v to one terminal and brush the +12v over the other terminal briefly.
Once the engine runs the injectors will gradually self clean in a few minutes of running.
If you can get hold of a Bosche Noid lamp (only a few dollars ) you could test that you are getting a pulse to each injector connector
EDIT oops ! just seen the post saying you found the problem ...sorry should have taken the time to read the thread right through. Well done anyway
Can you hear the injectors clicking when you turn the engine over ?
If not disconnect all the injector electrical connectors and flash 12v across each injector in turn 10 -15 times to free up the injectors.
Each time you brush 12v over the injector terminal You should hear a clear and distinct click as the internal solenoid plunger hits one end of the injector then another click when it returns as the power is removed.
IMPORTANT do not apply 12volts to the injector for a sustained period even seconds could damage the injector. The technique is to apply the 0v to one terminal and brush the +12v over the other terminal briefly.
Once the engine runs the injectors will gradually self clean in a few minutes of running.
If you can get hold of a Bosche Noid lamp (only a few dollars ) you could test that you are getting a pulse to each injector connector
EDIT oops ! just seen the post saying you found the problem ...sorry should have taken the time to read the thread right through. Well done anyway
04-25-2009, 08:09 PM
#34
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Well, this will definitely help you. Its great that you found this stuff. You sound like you have a lot of automotive experience.
Be aware of the sharpness of the body where the front harness runs near the radiator. It can cut the wires.
There are grounds to clean in this area at the very front of the car, one to the left (passenger side) of the radiator and one to the right of it.
Have you removed your fuse box and cleaned it yet? If not, after you repair the critical stuff noted, don't wait too long to do this. My wife and I pulled an 86 fusebox this morning, cleaned it, and replace it by early afternoon. Replaced all fuses. Dremel wire brushes are good for this job.
The fan and inlet air box is just above the fusebox. Its sealed with tar adhesive strips. it leaks and the water corrodes the fusebox. The housing has a single HVAC diaphragm also, that you need to replace when you go into it. ( I got my car mechanically right, cleaned the fusebox, then did this job a year later). While in there, you need to squirt oil on the fan shaft. Rog100 can supply the diagphram.
Be aware of the sharpness of the body where the front harness runs near the radiator. It can cut the wires.
There are grounds to clean in this area at the very front of the car, one to the left (passenger side) of the radiator and one to the right of it.
Have you removed your fuse box and cleaned it yet? If not, after you repair the critical stuff noted, don't wait too long to do this. My wife and I pulled an 86 fusebox this morning, cleaned it, and replace it by early afternoon. Replaced all fuses. Dremel wire brushes are good for this job.
The fan and inlet air box is just above the fusebox. Its sealed with tar adhesive strips. it leaks and the water corrodes the fusebox. The housing has a single HVAC diaphragm also, that you need to replace when you go into it. ( I got my car mechanically right, cleaned the fusebox, then did this job a year later). While in there, you need to squirt oil on the fan shaft. Rog100 can supply the diagphram.
Thanks for the help.
Jeff
04-25-2009, 08:13 PM
#35
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if you haven't had the car running for a few months or more my guess would be sticking injectors. Additives in the gas become laquer when the fuel has evaporated.
Can you hear the injectors clicking when you turn the engine over ?
If not disconnect all the injector electrical connectors and flash 12v across each injector in turn 10 -15 times to free up the injectors.
Each time you brush 12v over the injector terminal You should hear a clear and distinct click as the internal solenoid plunger hits one end of the injector then another click when it returns as the power is removed.
IMPORTANT do not apply 12volts to the injector for a sustained period even seconds could damage the injector. The technique is to apply the 0v to one terminal and brush the +12v over the other terminal briefly.
Once the engine runs the injectors will gradually self clean in a few minutes of running.
If you can get hold of a Bosche Noid lamp (only a few dollars ) you could test that you are getting a pulse to each injector connector
EDIT oops ! just seen the post saying you found the problem ...sorry should have taken the time to read the thread right through. Well done anyway
Can you hear the injectors clicking when you turn the engine over ?
If not disconnect all the injector electrical connectors and flash 12v across each injector in turn 10 -15 times to free up the injectors.
Each time you brush 12v over the injector terminal You should hear a clear and distinct click as the internal solenoid plunger hits one end of the injector then another click when it returns as the power is removed.
IMPORTANT do not apply 12volts to the injector for a sustained period even seconds could damage the injector. The technique is to apply the 0v to one terminal and brush the +12v over the other terminal briefly.
Once the engine runs the injectors will gradually self clean in a few minutes of running.
If you can get hold of a Bosche Noid lamp (only a few dollars ) you could test that you are getting a pulse to each injector connector
EDIT oops ! just seen the post saying you found the problem ...sorry should have taken the time to read the thread right through. Well done anyway
Thanks for the thoughts.
Jeff
05-04-2009, 06:13 PM
#36
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Happy Birthday to me!
On my 50th birthday, the '82 928 that I've owned since last June finally runs! It was a stupid wrong fuel injection relay. It didn't help any that the schematics were wrong either. Thanks to the Rennlist and all my other shark buddies for helping me keep up the good fight knowing it would end up being something simple and stupid. We were right!
Still a ton of work to be done on this car but now I finally know it's worth doing.
I think I might have to go for a little drive. Now that's a birthday present!
Thanks again for your support and assistance.
Jeff Warner
PS. The Help Jeff Get His 928 Running Clinic scheduled for this Saturday is officially canceled. WOOO! HOOO!
On my 50th birthday, the '82 928 that I've owned since last June finally runs! It was a stupid wrong fuel injection relay. It didn't help any that the schematics were wrong either. Thanks to the Rennlist and all my other shark buddies for helping me keep up the good fight knowing it would end up being something simple and stupid. We were right!
Still a ton of work to be done on this car but now I finally know it's worth doing.
I think I might have to go for a little drive. Now that's a birthday present!
Thanks again for your support and assistance.
Jeff Warner
PS. The Help Jeff Get His 928 Running Clinic scheduled for this Saturday is officially canceled. WOOO! HOOO!
05-04-2009, 08:36 PM
#38
Rennlist Member
Happy Birthday, nice present.
Can you say a little bit more about the schematics being off? Am hoping I didn't misread them and give wrong advice in the process.
Can you say a little bit more about the schematics being off? Am hoping I didn't misread them and give wrong advice in the process.
05-04-2009, 11:13 PM
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Thank you for your insight.
Jeff
12-02-2009, 08:55 PM
#41
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IT'S ALIVE!!!!
I finally found the problem. It was a ground wire. On pin 5 of the ECU is shown in the wiring as a ground. If you unplug the ECU and measure it was open to ground. Traced wire out and found that it goes directly to the temp sensor II. Took a jumper and tied it to ground. Turned engine over and I had pulses to the injectors.
Boy is that a trill after this long! Hurried and put plugs back in and assembled everything else that was loose. Tried to start it and it turned over about twice and then just sit there and ran.
I still haven't give up the idea of swapping out the Bosch for an after-market controller. But I sure feel alot better knowing that the engine is sound. Took a listen to the injectors while it was running and a couple of them don't snap quite as sharp as the rest. Probably wouldn't hurt to pull them and send them out to be cleaned and tested.
Just wanted to thank everyone that replied and let you know the outcome. Anyway Thanks Alot!
Lonnie
I finally found the problem. It was a ground wire. On pin 5 of the ECU is shown in the wiring as a ground. If you unplug the ECU and measure it was open to ground. Traced wire out and found that it goes directly to the temp sensor II. Took a jumper and tied it to ground. Turned engine over and I had pulses to the injectors.
Boy is that a trill after this long! Hurried and put plugs back in and assembled everything else that was loose. Tried to start it and it turned over about twice and then just sit there and ran.
I still haven't give up the idea of swapping out the Bosch for an after-market controller. But I sure feel alot better knowing that the engine is sound. Took a listen to the injectors while it was running and a couple of them don't snap quite as sharp as the rest. Probably wouldn't hurt to pull them and send them out to be cleaned and tested.
Just wanted to thank everyone that replied and let you know the outcome. Anyway Thanks Alot!
Lonnie
Hi Lonnie G.
I had the same problem on my 83 928s. I read your post, grounded the tan wire on the temp 2 sensor and she fired right up today. Running fine. Dont know why these cars lose the ground to the fuel injectors. I was almost at the end of my rope too. I dont know if you are still a member on this forum. But, I Just want to say Thanks for sharing the solution to your no start problem.
Joe Flash Porsche
Last edited by flash porsche; 12-03-2009 at 10:01 AM.
