When I have a misfire I check these thing. Coils, Wires, Plugs and fuel System. In that order. The fuel system is last because a problem there should affect all cylinders not just one. Unless its an injector.

 

Sorry I couldn't make a new post for some reason.. Figured this was close to my problem so I'd post it here.


I just purchased my 2nd Monte after loving the first one so much. This one has an issue I cannot figure out. Cyl 4 misfire... I've changed plugs, wires, coils, fuel filter and have no clue. I've tested the ohms on a multimeter and they're all reading around the same level.


I've noticed that this one compared to my other one is seeming to have more moisture coming from the exhaust, however there is no noticeable smell of coolant to indicate that the head gasket would be faulty. Without the coolant smell I'm doubting it's the head gasket.


Is it possible that the cat could be loaded and causing a misfire but not to the point of burning yet? I'm not noticing the rotten egg smell usually associated with a blocked cat but... I'm out of ideas.


Could the ICM cause a single cylinder to go out? How do I check the ignition control module to see if its faulty?

 

Hi Mike,
Take a look at your ignition coil related to cylinder #4. If your ignition module or coil is bad, Normally it would affect both those cylinders connected to that coil. (aka, cylinders 1 and 4) Your problem, as you explain it, is isolated to cylinder #4. You could have a Valve that is stuck open. I think, but I an not sure, the misfire code comes up when the sensor does not feel the right pressure from the explosion of the fuel air mix in the cylinder.
That could be cause in 1 cylinder by bad wire, plug, injector or valve, something related to that particular cylinder. Remember, your coil fire 2 cylinders at the same time to ensure max burn of the exhaust gasses.