'96 Chevy Z71... won't always start after installing 2 Fuel Pumps

Hello! Glad to be a new member of the boards!

I'm having some problems with my truck. Recently, the key wouldn't turn anymore so we had the tumbler replaced. About a week after that, the fuel pump started giving us problems.... most of the time the motor would just turn over, but every now and then I'd get lucky and get it to crank.

Well, luck ran out and I had it replaced. Ran great for a few days, and then the problems slowly started happening again... motor would turn over repeatedly, and every now and then I'd get lucky and it would start. Once it starts, I'd have no problems whatsoever. The last time I was able to get it to start, we got beneath the tank and jiggled the wiring around, and it started.

That got real annoying to do every time, so we had a brand new, ACDelco pump installed. Worked great for a few days, and then the same exact problems reoccurred. Sometimes the fuel pump would activate and start, most times it would not. We also changed the relay, and everything is firing properly.

Somebody please help. I'm not ready to sell the truck, but I'm not ready for it to become a money pit... It's got 240,000 miles on it.

well, if you jiggled the wire and that helped, would start there. could be just a loose ground. when the truck is giving you these problems, can you hear the pump run for 3-5 seconds before you try to crank it over?

Thank you for your reply. When it's going to start, yes - I can hear the fuel pump activate for about 2 seconds. If it doesn't do that, it won't crank.

Cheack that ground that 16th hippy mentioned. It should be on the outside of the frame rail on the drivers side, right by one of the bed mounts. Take it apart and clean the frame. I usually replace the screw and the wire terminal(s).