91 Pontiac Grand Prix (Popping from throttle body)

[chamblizi]

Hey Phil, I been working on my friends vehicle for the past two days. The Pontiac starts but it sat for 6 months... So we got it to run but its making popping sounds.... through the throttle body, and popping thru the exhaust.

What is going on...

1 thing that could be wrong (I did not change the last spark plug in the rear)

other then that what causes a pop in the exhaust and through the throttle body?

[GTP Dad]

The first thing you need to do is a compression check. With popping through the throttle body and exhaust you either have burnt valves on an intake and exhaust valve or sticking valves in a cylinder. This can happen if a car sits for a while but is unusual. The compression check will enable you to find out which cylinders have the issue and you can go from there. The only other possible explanation is a bad cam shaft that is causing the valves not to close.

[chamblizi]

Originally Posted by GTP Dad

The first thing you need to do is a compression check. With popping through the throttle body and exhaust you either have burnt valves on an intake and exhaust valve or sticking valves in a cylinder. This can happen if a car sits for a while but is unusual. The compression check will enable you to find out which cylinders have the issue and you can go from there. The only other possible explanation is a bad cam shaft that is causing the valves not to close.

Thanks but i fixed it... IT was 3 spark plug wires hooked on wrong from the previous owner. I re did the three and now its fine .. now i got to swap the alternator for my customer.