I bought a 94 a-4 with 373s, runs great but tcc doesnt lock up, have a mech, friend who scanned it and he could enable it manually, but pcm doesnt kick it on, also have a donor pcm out of a 94 caprice, put it in and the tcc would work but the donor had 273s and my car idled like **** at first but then got better as it warmed up and drove around but when i turned it off then later restarted it did the same thing all over again, like it had to relearn itself, and the 94 caprice has has 2 knock sensors, whats up with my f-body pcm and why doesnt the donor one work good?

 

Has your speedometer been recalibrated for 3.73 gears? If so, it is possible the TCC lock/unlock tables were not scaled accordingly, or correctly. Also, if there is a problem with the throttle position sensor, or its adjustment, this could cause the TCC strategy to not work correctly.

The B-body cars used a different sized MAF, and as such, the MAF calibration is different between the B and F body cars.

 

original pcm has been recalibrated, but if problem with tps then why would donor pcm let it work, what has to be done to the MAF?

 

I still have the maf from the doner, can i use that with the doner pcm?

 

Yes, although there are other things that are different, too, like the fueling and spark advance maps. But it should at least run a little better with the proper MAF.