I have a 96 grand prix that keeps stalling on me. In park the engine rpms will go up and down and then just stall. Also when your on the road and let up on the gas the engine will stall. It starts fine and runs fine but keeps on stalling. This just started and could use some help. If you keep the rpms up it will not stall.

 

sounds like the fuel pump.

when you start it have someone smack the underside of the fuel tank, it will bump the pump and get it working again, if it idles ok then, then I would suggest its the fuel pump.

 

there are several possible causes why car stalls. here are some things that you might want to check: fuel pump as well as the gmc fuel tank; bad oxygen sensor; fuel filters; low transmission fluid; weak spark. by the way, when was the last tune-up and oil change?