Why does my truck's fuel gauge gets stuck at full? It will work after a while. How can I fix this? 2001 F250 with 5.4 v8.

 

Do not leave the ignition in the on position while fueling.

 

I don't do that. So, it's something else.

 

Bad quality gasoline such as what they sell at the wholesale clubs and non-branded gasoline and NON top tier gas that have NO additives will cause this.

Do your engine a favor and run Quality gasoline from only top tier suppliers, run a double dose of Chevron Techron fuel system through a couple of tanks........this should fix it.

 

besides the above... and all is true.

broken wire (open) can cause it.. a bad sending unit inside of gas tank.
bad ground or broken ground wire.
bad gauge in dashboard. or wires to it.

and being intermittent.. even a good tech will have a problem locating it. ( Time )

you do have a 15 year old truck. everything is wearing out. a little at a time
.

 

So, it's dirty inside the tank? Is that what is causing it to stick? I think I should remove the tank and clean it out and replace the entire pump and assembly.

 

A couple of other ideas to consider:

1. There's a wire on the level assembly. It might have gotten tangled with the level arm and it's stuck in the FULL position.

2. How low do you usually run the tank? The fuel in the tank keeps the unit lubricated. If you consistently run below 1/4 tank you might not be lubricating the assembly.

My gauge occasionally sticks and it works itself out within a couple of days. The cost (and time) of replacing the level unit INSIDE the tank is near the bottom of my list.

 

Mine did this once or twice and resolved itself, not sure why it happened but I am glad it is working again.