1998 Pontiac Sunfire problem

Whens the last time you had a tune-up? A common problem with these cars is the holder that contains the coil/wires. It's the piece you have to remove to access the spark plugs. Usually the spark will short to ground through a faulty component in that unit. Remove it and look for burn marks or white marks that would indicate a a short to ground.

Your problem sounds like a mis-fire and that's where I'd start with your vehicle.