Little confused about this car I'm working on. Car runs fine on stock ECU but when I put the powerFC in, it doesn't fire. Observing the commander, the RPM does not move. I have checked that all the sensors are working and it did have a bad TPS but I replaced that and it is now working but there is still no RPM signal when cranking.

I pulled a known working PowerFC out of my RHD and it did the same thing. ECU ground is connected to the chassis and the UIM to firewall is also connected. White CAS connector is on top as well. I looked at the wiring schematics and the CAS sensors go straight to the ECU with no interruptions. It's already late and ran out of sunlight but has anyone experienced this before or have any ideas? What really has me confused is it works fine on the stock ECU o.O

thewird

 

This car is driving me nuts. It doesn't make any sense o.O . Why does it work with the stock computer but not 2 tested working powerfc's...

I've cut out all the useless **** since this car is non-sequential and changed the crank sensors. I'm running out of things to test/eliminate.

I just know its going to be something retardedly stupid...

thewird

 

Got it working but I changed so much I don't really know for sure what fixed it LOL.

thewird

 

It might have been a loose or poor connector acting like the AC does with the PFC.
The PFC requires signals more precise than the stock ecu.

 

Stock ecus will start and run with bad sensors. Glad you got it fixed.

 

Oh forgot to update the thread. The problem came back the next day after I thought I had fixed it. My last resort at fixing it solved the problem. I stripped an old harness i had lying around and removed the crank sensor wiring and ran separate wiring for the crank sensors from ecu to sensor. It fixed the problem.

thewird