DME wire, Oil pressure, fuel pressrue, LR MAF question
06-06-2004, 12:00 PM
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DME wire, Oil pressure, fuel pressrue, LR MAF question
Update on putting my '86 951 back together and a few questions.
When I was looking at the DME to see if I pulled a pin out of it by accident when I was installing my A/F monitor I noticed electrical tape wrapped around a few of the wires individually on the harness. The one of interest is the thick green wire that carries the O2 sensor signal and splits at the harness to the DME to pins 24 and 25 I believe. Well this big thick green wire is the shielded wire or something and it looks like someone tried to use a vampire clip on it and the wire is all messed up. Is there anyway to fix this or do i need to get ahold of an old butchered engine harness and replace that wire.
The engine 100% back together, again. Now it cranks and builds oil pressure slowly to 5. Immediately after turning the ignition off the pressure drops very quickly to 3 and over the next few minutes continues to drop to just above zero. To make a comparison I started my '84 944 and oil pressure builds immediately to 5 on a cold start up and then slowly falls at a steady but much slower rate than the 951 did to just above one. I do have the OPRV that has the spring and plunger setup, can you put that in wrong? If not the OPRV what else could cause this?
The engine cranks, after getting a new starter, I have spark, I have fuel, I have a brand new DME relay, power to my MAF but no start. From reading other no start posts i noticed that people asked of the tach was bouncing, I honestly can say i did not notice that so i will check that. If the tach is not bouncing what does that mean?
I have new 55lbs. injectors and from my fuel rail gauge I see that pressure builds as it should when the pump turns on. Problem is i noticed the pressure dropping almost immediately when i turned the key off and after letting the car sit over night the rail pressure was at 0 psi. I have a hard time believing my brand new injectors ar at fault but, what all can cause the rail pressure to drop to 0 psi over night?
Anyone with a Lindsey racing MAF not have two black wires in the harness provided? The directions say to hook one black wire to a body ground and the other one of the original AFM wires. I only had one black wire in my new harness and hooked it up the original wire from the AFM. What did you do?
Thanks for the help and ideas
Tom
When I was looking at the DME to see if I pulled a pin out of it by accident when I was installing my A/F monitor I noticed electrical tape wrapped around a few of the wires individually on the harness. The one of interest is the thick green wire that carries the O2 sensor signal and splits at the harness to the DME to pins 24 and 25 I believe. Well this big thick green wire is the shielded wire or something and it looks like someone tried to use a vampire clip on it and the wire is all messed up. Is there anyway to fix this or do i need to get ahold of an old butchered engine harness and replace that wire.
The engine 100% back together, again. Now it cranks and builds oil pressure slowly to 5. Immediately after turning the ignition off the pressure drops very quickly to 3 and over the next few minutes continues to drop to just above zero. To make a comparison I started my '84 944 and oil pressure builds immediately to 5 on a cold start up and then slowly falls at a steady but much slower rate than the 951 did to just above one. I do have the OPRV that has the spring and plunger setup, can you put that in wrong? If not the OPRV what else could cause this?
The engine cranks, after getting a new starter, I have spark, I have fuel, I have a brand new DME relay, power to my MAF but no start. From reading other no start posts i noticed that people asked of the tach was bouncing, I honestly can say i did not notice that so i will check that. If the tach is not bouncing what does that mean?
I have new 55lbs. injectors and from my fuel rail gauge I see that pressure builds as it should when the pump turns on. Problem is i noticed the pressure dropping almost immediately when i turned the key off and after letting the car sit over night the rail pressure was at 0 psi. I have a hard time believing my brand new injectors ar at fault but, what all can cause the rail pressure to drop to 0 psi over night?
Anyone with a Lindsey racing MAF not have two black wires in the harness provided? The directions say to hook one black wire to a body ground and the other one of the original AFM wires. I only had one black wire in my new harness and hooked it up the original wire from the AFM. What did you do?
Thanks for the help and ideas
Tom
Last edited by pa944red; 06-06-2004 at 12:23 PM.
06-06-2004, 01:28 PM
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The instructions from the Lindsey MAF are a bit confusing. I would connect the black wire to a good ground at the DME or the chassis. Did you change any settings after you installed the 55 lb injectors? Even if you did and you have 55lb Siemens injectors without ballast resistors your car won't start (some cars start, mine didn't).
