General ECU question

[9t1TSi]

I have a 1991 motor with a 1991 ECU, and I'm putting them into a 1990 car.

My question is, does the 90 plug differ from the 91, and/or what would need to be changed on the ECU

 

[BoostedTalonTS]

According to this, it's more than just a pin swap on the ECU harness... This is actually for converting a 90 ECU to a 91-94 car, but you'll get an idea of what's different between the two versions.

http://www.ecanfix.com/~mdhamilton/ecuconversion.html


I guess it all depends on if you are planning to use the newer ignitor & coil pack from the 91 or not.

 

[NitrousBob]

Dont forget the throttlebody and ISC assembly is a little different too.