I just bought an old street rod that has undergone a TPI swap from an 89 Trans-Am. The PO changed the MAF to MAP.I don;t know why....... The car has a hard start situation, and hunts for idle when it does start, runs rich. and sometimes dies....... I borrowed a 730 ECM from a friend and it seemd to be better, at least it doesn't hunt for low idle, but idles fast approx 1200/1500 rpms.. and runs a little rough like a carbureted car would if it needed a tune up. MY question is ,can I change or reprogram the chip in the original ECM? or will I need to get a 730, and have it reprogrammed? OH and as a side note I did replace the O2 sensor, but have not gotten to the EGR valve yet, thought I'd seek advice before I went much further.... I am totally new to EFI systems, and am kinda in the dark here. Thanks in advance for any help thrown my way.

 

If it was an 89 MAF car and now is a MAP car, it should have the 730 ecm in it already.

Car sounds like it just needs the basics and reprogramming of the chip for the motor being used. Shouldnt take much to get it to work however unless the motor is a wild setup.

Fast idle sounds like vacuum leak and/or way too much timing. Check the overall mechanical state of the motor for leaks and proper base timing which is 6-8 degrees. Set min idle with IAC sensor disconnected and then reconnect it after the throttle screw is adjusted.

Check the o2 sensor and from there it should run if you have the right chip and all the wiring is done correctly.

If not, may need to check the wiring to make sure the swap was done correctly.