Hey guys i need some help here.

After a long time rebuilding and planning the single turbo setup the car, finally started with the Apexi PFC. I did some minor adjustments like higher idle RPM and disabling the NON sequential setting and 02 sensor setting. And the car fired right up... I didn't even have the 4 wires cut yet!!!!!

It ran very smooth, idled perfectly even with A/C on. But i had to shut it down after seeing some oil leaks. To make a long story short. After removing and reinstalling the tranny, tried starting car and didn't work. After checking plugs, grounds etc etc adjusting some, it almost wants to start, but doesn't. Cut the 4 wires, no results. Checked the plugs and spark multiple times. Have fuel pressure/spark etc... Reset the Apexi multiple times as well....

Everything is highlighted 4.99volts. All sensors, pretty much all of them...

Put the stock ECU in and the car fires right up!!! Idles rough with engine check but it runs !!!

What am i doing wrong??? Every ground seems to be in place...

Is the unit fried?? Any help is welcome!!!

 

You have to think of what you did between the "it was working" and "tranny fix and now not working". Things do not just go bad that easily.

You did something or did not do something to cause it.

A sensor reading of 5 volts normally means it is bad or no electrical connection.
Find the wiring that you hosed or forgot durying the tranny fix.

 

I know i've checked the wiring couple of times, but it's strange cause the stock ECU does work.

I had to remove the tranny cause the collar/o ring was not in the right way, I've only removed the UIM. Everything is hooked up the way it should. Tranny bolted back on, installed the plugs in the tranny. Reconnected the 2 ground wires on the tranny. Pretty straight forward job, did not touch anything else.

Only thing i can think of right now is that maybe a fuse is out, i will check that today. Or the Apexi ECU is not getting the full 12Volts.

Fuel pump is priming, can hear the relay's clicking. I will check for spark again later this week.

 

Well i tested for 12 volts on the ECU connectors and i have measured atleast 5 solid 12 volt points.

I've also checked all fuses. Everything seems fine.

I'm thinking to test the unit on another FD. I'm all out of ideas now....

 

Any ideas???

 

How about the two grounding wires?

 

Yes that's probably the root of the problem, cause i can;t think of anything else. The sensors probably use that to ground themselves.

These ground wires come out of the loom, center of the UIM. They both are in the same o ring connector and i've connected them to the Tranny. Do you think this is a good ground point? Isn't the Tranny aluminum and does it conduct?

Car ran fine last night with stock ECU btw, not smooth cause the stock ecu was having a hard time dealing with all the engine checks. .

Another strange thing is, with stock ecu i don;t hear the fuelpump prime. When i install the Apexi i do hear it prime.