Hi, I have had several electrical problems with my 7... I had the computer unbolted from the floor for testing because my car wouldnt get any spark. Fixed the spark issue, and rebolted the ECU to the floor... Now, if the ecu is bolted down, the car will no longer spark the spark plugs. If I unbolt the ECU so its not grounded to the floor, it will start up great. I noticed if I turned the key on, and just touched the ECU to metal, it makes little sparks where it is touching metal like its shorting out. What would cause this? There are several different grounds going into the ECU via the wire harnesses and they dont screw anything up. Its just when the metal casing of the ECU touches metal... Any ideas? Thanks

 

Tawd - There's plastic sheets inside the ECU casing, to prevent grounding of the boards inside. you probably jolted something like this out of place when you were moving it, or pierced it. just take the covers off, an make sure that they're not touching aything they shouldn't, and that no wires came loose. You can't really mess anything up on the inside so don't worry too much about it, just take a peak

Double check all the wires going into it, too, to make sure they're not split/grounding out, etc..

 

Hi, Thanks for the reply. I took both covers off and both of the clear plastic shields are still on the covers. Also, I removed all 3 wire harnesses from the ecu. I plugged them back in 1 at a time. plugged the little one in, and grounded the ecu to the floor and it made little sparks... Unplugged that one and plugged in the med. size plug and grounded the ecu on the floor and it made little sparks... likewise with the 3rd plug. So, with any of the 3 plugs plugged in, its shorting out something in the computer. I think that pretty much eliminates a wiring problem doesnt it? I have tried 2 different ecu's and they both have the problem.

I covered the mounts in electrical tape so I could put the ECU on the floor without it grounding out and it seems to be working ok... I just dont like things being rigged up so I would like to figure this out. Any other ideas would be great! Thanks

 

While driving for the next few days, try to notice something that does not work that is a part of the ECU's circuitry. Maybe that electrical item is shorting out inside the ECU and you could trace it back that way. Personally I'd just buy another ECU and keep that one as a spare for what if situations. There's flaws to that idea though that I won't go into.

 

Thanks for the reply. I cant drive the car for the next few days. I havent got it tagged yet. I have just been running it in my garage, and down my street. The only thing that doesnt seem right with the engine is it doesnt like to rev up past oh say 3500 rpm... It just studders and stinks like its really rich on gas. the fuel injectors on the fuel rail are missing the locks on the electrical connections so that may be causing the car to stop revving at 3500 rpm. I have already tried 2 ecu's and both have the grounding problem.