Hi, My 1988 Trans Am 350 TPI, idles and runs fine with the EST wire disconnected. When the wire is connected, the car idles rough and stalls when put in reverse or drive. I've tried 2 different distributors and I still have the same problem. Can anybody help?

try a new ecm

check your base timing stock is 6 degrees before.

Hey Dean, did you rebuild the MSD distributor with new parts from MSD?

D.

Base timing is set to 6* before with the EST wire disconnected. With the wire connected it advances to about 16*+ & - but it's not a smooth idle.

Youve tried different dizzys with the same result. Its runs just fine with the EST disconnected you said. The only difference between EST connected and not, is connected the ECM drives the advance/retard function. Try a different ecm/prom.