Pontiac Problems? Ask a Mechanic for Answers ASAP
Try and switch wires. Sounds like you have wires 7 and 8 crossed.Also check spark plugs and make sure they are not cracked. A small black line indicates a crack
Maybe i can help. Northstar engines are notorious for overheating. Due to the opposition of the block and heads they tend to warp. A new engine maybe in order if you want to keep the car.