I have a 91 Cavalier as a beater with the 2.2 liter 1 bbl tbi system. I bogs and misfires under load in the very low rpms of each gear (no tach), but its fine in the upper rpm's. I figured a tune up would fix it, but it has coil packs and I dont know if those go bad? Anyways, any suggestions? I dont think its anything computer related as it runs fine except for about a 100-200 rpm span. My other idea was a new injector, but I dont want to / cant afford to just throw money at it.

Thanks!

 

Yes, the coil packs do go bad. My girlfriend and I used to own a 1994 3.4 Camaro and one of the packs went out and caused similar problems, except it was more like a wire was dead, just ran like crap all the time.

 

Well chuck it looks like you need to take it to smitty's speed shop over at 916 Stewart. On your way back to school go to the Zone and have them scan it real quick to make sure it isn't throwing any codes.

 

Does it do this at the same rpm everytime or at the same throttle position. It's real easy to check the throttle position sensor with an multi meter, anolog or digital.

Steve