I read in past threads if your gas tank guage needle is past the full mark its not the sending unit but a wiring problem in the system, and if the guage is below empty then its your sending unit, if mine reads past full should I change out the sending unit or start ohming out wires? could the guage itself be bad? Is there an easy test to confirm any of these possibilities?

 

I don't know about this one. We had an 85 F-150 that always showed above full when you topped it right off. A journeyman mechanic told me once that this is due to the fact that on the fuel injected vehicles you were only supposed to fill them to the Full mark to allow for the expansion of fuel once you're running. The warm fuel is circulated back to the tank... Plus there is a filter in the breather and to prevent it from getting soaked when you fill up you should not put any more fuel in once the pump shuts off automatically. Unless you are having different readings all the time or the gauge stops working altogether; I wouldn't worry about it. At least that is what I would do.

Don

 

From what I understand, showing above FULL is usually an electrical problem of some sort. If you're dealing with the original sending unit, that's probably the problem.

 

thanks for the info I'll drop the tank and change the sending unit and pump while I'm in there.

 

You may want to change the float too, even if it looks good. It's only about $5. I've learned the hard way to do everything possible on a gas tank while you have it down.

 

I will, I'm even thinking of just getting a polyethelene ( spelling?) tank thanks for the advise.

 

I just ordered a poly tank. Should be here next week. Am changing sending unit & float while I'm at it. Hopefully that will fix the gauge and I know it will solve one rust problem.