I have a 1991 buick park avenue with a 3.8 liter motor. It started running very poorly, so I checked to see if all of the cylinders were getting a spark. cylinders 5 and 2 produced no spark. At that point I replaced the coil and plug wires. Still no spark for 5 & 2. At this point I detached the coil pack and compared the input voltage to the coil packs. The pack that operates 5 & 2 had no input voltage and the other two packs had voltage. Where should I go from here?
Replace the module that the coils are bolted to.
There was no input voltage coming from the ICM? Then the ICM is probably bad or there’s a break in that little wire that runs to the coil pack from the guts of the ICM. Check the primary and secondary resistance of the coil to be sure that it’s not just a bad coil pack and you didn’t miss something, before you go and replace a sure to be expensive ICM.
He doesn’t need to do any additional checks. The ignition control module isn’t firing the coil, it needs to be replaced.
Success! I replaced the $105 ignition control module and she is running on all six cylinders! Thank you for your advice!
You are welcome. Glad I could help.