71ChevelleSS

Hey guys I had a bad turn of events. I have a 71 chevelle which I just completed my frame off on now working with engine and body and paint.

It has a 1987 firebird GTA 5.7 motor ecm and harness in it right now with a t5 trans.

My question is can I use a v6 ecm if I just swap the prom chip? From what I understand the v6 harnesses are pretty identical needing some changes and lengthening of wires to use on a v8.

My ecm is bad in the 87 and it is stil MAF so I am wondering about the v6 ecu swap cause I am sure my prom is good but bad board on the original ecm.

What about tbi computer? will a 88 5.7 tbi truck ecm work if I swap proms?

Please help as right now this is my only car!!! Thanks guys

ninetyone

iTrader: (2)

yes,swap out the prom. on the v6 ecm

71ChevelleSS

Ok one more question. I have a 87 l98 prom can i still use that prom on the 90-92 v6 ecu? Or will I have to get a 90-92 v8 prom?

Please let me know asap.

ninetyone

iTrader: (2)

https://www.thirdgen.org/ecminterchange That is the prom interchange guide. The 165 ecm is for mass air vehicles and I believe the 7730 is speed density. Sounds like you have a 7730 (speed density) ecm and need to use the 165 (MAF) prom. https://www.thirdgen.org/forums/diy-...-question.html Also look at that link, that guy is trying to do the same thing you are.

ninetyone

iTrader: (2)

sales@tbichips.com Harris Performance. That guy also does TPI chips pretty cheap. You would send your prom (MAF) to him and then he would send you back a custom high performance chip with the proper adapters,etc.

71ChevelleSS

Nice! Thanks alot for all your help bud. I owe you a beer!

camaronewbie

I'm confused - how can a V6 prom run/control & have fuel/timing tables for 8 injectors and cylinders?

ninetyone

iTrader: (2)

It can't .

camaronewbie

So I'm really confused then - the original question - isn't he asking if he can use a V6 prom on a V8 ECM board?

ninetyone

iTrader: (2)

I think he wants to know if he can just use the v6 emc and the v8 prom together,which I believe you can, however his situation is this: His engine and original ecm are MAF. So , he is basically asking if he can use his MAF prom with the speed density ecm. The 7730 ecms were speed density 1990-92 and the 165 ecms were MAF 87-89 if i am correct.