I just replaced the fuel pump (see this thread) at first it looked like the gauge didn't work at all. I just went to move the truck to the shade to begin removing the bed and before I started the truck it appears to be reading the proper fuel level. This is before I even inserted the key. After I started the truck the fuel gauge sunk to empty and the fuel light came on. I moved the truck and removed my key and it very very slowly rose to what appears to be the proper level.

I need some quick advice: what could be wrong with the truck or fuel sender? I'm about to remove the bed to see if I can adjust the fuel pump because I thought maybe the float was getting stuck.

 

Yes most likely the fuel sending unit is incorrectly placed where the float is getting stuck.

 

Just an update. We pulled the bed off and it appears the float was getting stuck. Where the filter should have been lined up seems to be improper for this pump, so I rotated it counter-clockwise a bit and it seems to work fine. All of the hoses and wires still fit nicely and now.