How would a engine run with a bad coil pack??

[cedgtp24]

mine putt putts when everything is warmed up and when I lay on the gas it vibrates untill it gets over 2k rpm and it smooths out. Usually when a car is in first gear and you slam on the gas the RPMs are suppose to race to red line, but mine climbs kind of slow. Also it surges when im crusing over 45mph. Does this sound like a bad coil pack because thats what im leaning towards.

[Doubt_Incarnate]

It sounds like a good guess. i dont know much about the DOHC motor but if its like the 2.8/3.1 each coil effects 2 cylinders so things should be pretty rough. If the ignition control module is faulty it may be missing the signal at the lower speeds, or telling the coil to fire once when it needs to, but not for the second time its supposed to. resulting in a miss on 1 cylinder. sadly it sounds like an ICM o me, but im no genius. i think coils are about 30 bucks new, ICMs are kinda on the expensive side when i last checked like 120 i think, dont take my word for it.
I've seen the 3 coils with the ICM for the OHV motors on ebay for like 20 bucks.

[manny]

Exactly. To locate your bad coil pack, do a spark test. If you don't have a spark test tool, just start your engine, and pull the spark plug wires, one at a time (not to worry, you'll be safe since our plug wires have the long extentions on them). If the wire you pull does not make a immediate impact on engine performance, that is the bad pack (perhaps). After you narrow it down to one coil pack, to be sure that it is the coil and not the ICM just switch the position of the bad coil pack with the one next to it. The non-firing cylinder should also change when you move the coil pack. If if changes you found your pack. If it stays the same, that section of your ICM is going bad and you should invest in a new ICM. Coil paks are $19.99 USD at autozone, and ICM's are about $95.00 USD.

If you do not find a bad coil or ICM you may have a bad injector which could cause the surging at 45 mph symptom.