Car is a '96 Formula. I was driving to the allergist when the car started running rough, with a bit of what feels like bucking. SES comes on. When I got back home I pulled the codes and it was for a bad ICM. I have noticed the car runs and idles smooth while cold, but the roughness/bucking feeling starts when it gets warm. Suppose that happens when it goes into closed loop. Procured an ICM, went out to swap the old one with the new one. Tied fuel lines etc, out of the way. Much to my surprise I couldn't find a socket, and I tried both SAE and metric, that would fit. Anyone know what size socket fits those two little bolts?

 

Shoebox lists the “ignition coil nuts” as 9/16”.

4th Gen LT1 F-body, Fastener Torque and Spec Matrix

I'd offer to measure mine but all that stuff is long gone….

 

The little screws that hold the ICM on might be 7 or 8mm or might be 1/4 or smaller SAE. I don't remember. Make sure you use heat sink compound.

 

Been out trying to find the right size, again. Still can't get a socket that fits. I've only dropped one socket I can't find, so I guess that's a good thing. However, I'm frustrated now, so I'll wait until tomorrow before trying again.

 

The two screws are 7/32. I got the new ICM on, car still running rough, but the SES hasn't come back on, yet. I'll go out, after supper, and see if any codes can be pulled.

 

Took the car on a grocery run this morning. Still running rough. Not trying to stall or shut down, but it's like stuttering. SES hasn't come on, and my code reader says zero codes. Bad gas was mentioned to me, but I haven't heard any pinging.

 

Check your plug wires for burning or arcing. U can try misting them with water bottle @night