Hi I'm new this is my first post here. I just naught a 94 Chevy c1500 changed the fuel pump and everything was fine. About a day later I was driving and the gauge jumped from 1/4 tank to 1/2 tank and hasn't moved since. Not sure where to start on this any help is much appreciated thanks.

 

My fuel gauge jumps all over the place, whenever it feels like it. I was told it was my sending unit, and since it's part of the fuel pump, and the fuel pump is in the tank, I have learned to live with it. I'm guessing you may have the same issue, or an issue with the gauge itself.

 

The two things that could cause this are the gauge itself and sending unit. If you had a broken wire or shorted wire the gauge would read either full or empty, not stick in the middle. The '94 model was still able to change just the pump and not the whole unit(module) correct? If so I also concur with Pickup Man that the sending unit is the most probable cause.

At least it is fairly easy to get the fuel pump out of those trucks, if you pull the box off.