Ok, I have a 94 Pontiac Grand Prix, 3.1 V6 with 162k miles on it. Once
> again, the wife complains that the car is running rough. She get's home, and
> sure as shit it is.
>
> I test the plug wires, and one of them isn't quite up to par. So I return
> the wires and reload em. The misfire continues. I removed the alternator,
> and checked all the plugs, non of them seem fouled (which you would like one
> would be if she was misfiring). I've removed each wire, one by one from the
> ignition coils while the car is running. No noticable difference is made. I
> checked the front three wires, by removing the boots from the plugs, while
> the car was idling, one by one, and you could tell a difference in the way
> the car ran. All affected the idle about the same. I will do the same of the
> other three plugs tomorrow when I can get someone to turn the car off. Am I
> missing something in my diagnostics? Could I have a bad plug, and not be
> able to tell? Can you check the resistance of plugs like you can wires? When
> looking for strong spark, should the spark color be orange? I almost assumed
> the timing was off, but she fires right up. I wacked the computer gently a
> couple of times, and no difference was noticed ..
>
> Please help, this is REALLY starting to piss me off.
>
>