My story:
Ive been chasing a mis-fire gremlin in my car for the last 3 months. I get it running fine and then about 2-3 weeks later its mis-firing again.

All new plugs and wires. New injectors in #2 & #4(x2). New coils for 2/5 and 1/4. Compression checked out fine. Leak down was acceptable. Fuel pressure is fine. AutoZone said the ICM was fine. Fuel injector light shows all injectors have a strong electrical pulse to them.

Driving it home from work yesterday and started mis-firing AGAIN! Got it in the garage and did a little bench diagnostic. Took a thin piece of metal and layed it across the intake. Individually pulled the wires off of the coil posts. Pulled the injector fuse and spun the starter. Checked to see if the coil posts would arc to the metal strap. All of them arced except for 2 and 5 which did absolutely nothing. Obviously 2/5 is a dead coil AGAIN.

My question:
Why is it that i just replaced this coil 2 weeks ago and now it is dead again? Is my ICM crapping out eventhough Autozones test said it was ok? Could it possibly be a combination of the ICM and ECU? Was it just an unlucky junk coil? Is it possible that something in the emissions system is causing the electrical to go haywire(doubtful but questionable)?

I need some kind of advice. I am about done with this car. Nice looking no where near reliable.[/align]

 

There should be a warranty on the coil, so definitely go get that replaced again. Otherwise youve gone that far why not replace the ICM? We test things at OReillys and although its semi accurate by no means is it always right, their machine could be wrong.

 

Someone just posted about having problems with his car. We said alternator, he went to AutoZone and it tested fine. He went ahead and bought a new alternator, and voila! It fixed his problem. Moral of the story is the auto parts stores aren't as accurate as you would like. I would look into a new ICM. Not sure how to check the ICM, unless you remove the coil and check for voltage while it should be firing.