I have a gas gauge(?) problem. It sorta works. When I fill up, it goes to three-quarter tank insted of just over full like it used to. So I figured it was a quarter tank off but when it gets to E I get nervous and fill it and it takes ~13 gallons. The gas light'll come on occasionally.

What do you think, tank floater, gauge, sending unit, something else?

[Did a search, nothing helped.]

..Oh yeah, its an S4 n/a.

 

Ya didn't search hard enough then.

You probably have corroded and/or loose wires and/or connectors. Check & clean all connectors. Be prepared to remove rust. Make sure all the connectors are tight (gently squeeze holes with pliers?). You can measure resistance on a multimeter to make sure. Replace any wires that have more than zero resistance. The added resistance from the connectors and/or wires keeps the gauge from ever reaching "full". That would also explain why you have still have the full range, and why your gas light some times comes on - loose connector.

A bad sender is also a possibility, but the symptoms are usually different (like mine, see below). It's inside the fuel tank. Drop the fuel tank, replace the fuel strainer by the fuel pump while you're at it. If you ever want to exceed 250HP, now's a good time to upgrade your fuel pump. Otherwise a bigger fuel pump will just waste power.

But you're lucky it isn't worse. Mine goes up to F but on the way down it goes straight from 3/4 to E (even though it still has 3/4 left). I haven't bothered replacing it, especially since my gas light works fine. Yours is still "working", for now, and I think you could just ignore the problem.

 

Hey wow thanks! Thats really helpful. Only thing is where are these wires and connectors I need to check?

Sorry for the dumb questions lol.

 

They are on the top of the fuel pump most likely. I think there is an access point in the hatch area under the carpet. From there you should be able to get to the fuel pump and wires.