NFC94GT

I have a '94 GT with quite a few mods. AFR heads, ported Cobra intake, BBK long-tube headers, Dr Gas X-Pipe, Anderson CAI, 75mm TB, 24# injectors, etc. My older brother owned the car before me and installed a tunable chip in the PCM. He doesn't recall the brand of the chip. Recently, the car won't hold an idle and feels like it is running on 6 cylinders and extremely rich. Had the OBD checked and it trips a 511 code which, of course, is to replace the PCM. My question is - does anyone know if a '94 Cobra PCM will plug directly into a '94 GT? If so, are there any issues with running a Cobra PCM instead of a GT PCM? I would prefer to go after market on the PCM for a fully tunable PCM so I could get the car dyno tuned. Any suggestions for after market PCMs? Thank you for your input!

AdderMk2

you dont need a new PCM... remove the chip, clean off the contacts and re-install it.

511 code usually pops up when the KAM is disabled in the tune, or is the car is forced to run in open loop

and if you want the car to be "fully tuneable" buy a Moates Quarterhorse

NFC94GT

Thank you for the reply. I will clean the terminals, reinstall and see what happens. Also, thank you for the suggestion on the tunable PCM. I will let you know what happens.

NFC94GT

AdderMk2,

I disconnected the PCM and chip, cleaned the terminals and reinstalled. I also had the battery disconnected during this time to reset the KAM. I reinstalled all parts and started the car. Same ignition issues. It won't find an idle and sounds like it is running on 6 cylinders. One thing that baffled me was when I checked the plug wires for a miss, I noticed that the even numbered cylinders were firing sporadically. My guess is that the PCM is shot or the unknown after market chip is not sending the correct BIN. Please let me know if you have any other suggestions. Also, do you know if a '94 Cobra PCM will fit the wiring harness of a '94 GT? If so, do you know where I could get a hold of a Cobra PCM?

Thanks!

AdderMk2

again, i highly doubt the PCM is your problem. try removing the chip entirely and running the car again. If it still runs the same way, i would suspect the distributor or TFI module before thinking that the PCM is bad

Bubba 95SN

PCM does not make for ignition misfire.