Engine Performance problem
1984 Pontiac Parisienne V8 Two Wheel Drive Automatic 90,000 miles
hello. I have and 84 pontiac parisienne with around 90,000 miles. It has a chevy 305 motor. Problem is, under light throttle I have a random miss and backfire. If I accelerate, and get up to around 40 the miss for the most part goes away. At around 25-30mph the miss is pretty bad. When keeping my foot on the throttle it makes the car jerk. I have put the car in park and revved the engine, and it does it at light throttle that way also, but if revving faster it pretty much goes away. I have also had problems with this car dieseling, or running backwards a few times. Could this have messed up the timing.