Pontiac Repair: Ignition system problem on a 1992 grand am, ecm, grand am

Question
What would prevent a spark at cylinders 1 &4 , if the ignition module , coils and coil housing cover all test good ? could it be the ECM ?

Answer
Hi Dave:

Yes it can be. There are seperate drivers for the coils so it could be. If you have a wiring diagram for that car make sure you have continity betwwen all the wires that run between the igniton module and the ECM. when you say those are are "good" do you mean you already chnaged them chasing this problem?  If all the parts were changed that you mentioned and it still is minus spark on the 1/4 coil I would say it's a good bet.. considering you chnaged all the other parts.. But make sure the wrining is good. This is an odd one the ecm's USUALLY do not go bad for this issue Other issues YES!
.... Good luck :)