I have a 99 GA with 3.4 V-6 SFI. When I bought this it had a small misfire that I assumed would clear up with new plugs, wires, etc. System never threw a code but you could a stumble anytime you tapped fuel.

I put new Autolite Platinums, new 7mm wires, checked all connections, ohm tested all wires, put injector cleaner through system, etc. After this system starts throwing a Cylinder 4 misfire code, go through again and check everything, clear code, stumble still there, new code Cyl 1 misfire, find I had cracked plug at Cyl 1. Replace with new, check all connections, another Cyl 1 misfire code, so I replace the 1-4 coil. Still misfires, check all connections, nothing obviously wrong.

So I put an 'Ignition Spark Checker' (noid light?) in the spark plug wire and find a random bright spark among consistent low level sparks. I put this light in all other spark plug wires and the spark is nice and bright with no misfires or off beat bright spots. :eek7:

I can smell excess fuel in the exhaust, but I have checked the fuel injector wiring and they all appear intact.

Due to the random bright sparks I am still looking in the electrical department.

This morning the CEL shows a random misfire code.

I took the ICM out and had the local store check it and they tell me that they ran 4 different tests and the ICM checks out OK. They said the ICM was even hot when they ran them and it never failed.

What gives? What am I missing?:crying:

Well you won't believe this but I sorted it out.

Turns out I had accidentally mislabeled wires 4 and 6.!!!!!!!!!!! What an idiot!:banghead: :chair:

Now it runs like a top!

Thanks for taking the time to read this.