i have a 91 camaro with ecm #1228746, im trying to swap the ecm with one from aa full size p/u, #1227747. the pinouts are the same. but it dosnt run as well with the 1227747. the reason im using this ecm is because ive had a custom chip made for it and want to use it. ive read where guys have did this swap, but havnt found any info on it. has anyone done this swap or know anything about the ecms?

 

any help? even tho the pinouts are basicly the same should i change wiring harnesses? get one that is ecxactly match for the 1227747?

 

what year is the full size truck ecm? it may have same number of pins, but the actual wires might be off. i don't believe the truck one will work right tho.

 

88 - 91. both pinouts show to be the same except for about 4 wires that the truck didnt use. took those ou and no change.

 

next question is, are both ecm's from same size motors, or is one a 305, other a 350? if this is case, then def not interchangeable.

 

the camaro wiring is a 305 and the ecm is a 350 (1227747), what would be the dif? both call for the same ecm

 

the difference is in the programming. the 305 doesn't need the amount of fuel going into the motor that the 350 does. this factor alone affects the idle air control, the vacuum, and the timing.

 

im actually running a 383, using the 350 injectors, .495 lift cam, 7747 ecm with a custom made chip.

 

elaborate on how it runs. how does it idle, how well does it take off, cruise, noises, pops, anything. define what you mean by it doesn't run as well.

 

the idle is fine, has a bad dead spot if you accelerate fast, goes dead, accelerate slow and its ok. the fuel trims are 128 which is perfect, but it runs rich, sweats out exhaust, blows soot. the camaro ecm accelerates great, but not a good idle because of the cam