I have a 1985 mpfi with the 1226870 ECM. Today, for ****s and giggles, I threw a spare 1227302 ECM from a 1986 firebird MPFI into my car, just to see what would happen. It ran fine...a little bit richer then my ECM based on the BLM count. The idle was a bit different too. Is there any obvious advantages to the newer ECM that would make it worthwhile to swap? The car runs like a dream with either ECM. Although, the 1227302 is from a 5 speed, so it naturally didnt lock my torque convertor.

 

Generally, the newer the ECM the better the code. So the newer ECMs typically run better. I wouldn't recommend running a stick calibration on an auto car. The other way tends to work OK, but not always.

RBob.

 

I noticed that it did run much better on the cold start. My regular ECM runs a bit rough for a bit until it warms up. This one ran great the whole time. If I happen to go to a junkyard and see an auto with the 122702 i'll grap its memcal. Thanks for the reply