my 87 GT has a problem with the gas gauge, it is always reading at a full tank, and the dummy light for low fuel only comes on when there is 1/16 a talk left or less, i know its supposed to light up before that
so...
whats wrong? and what do i have to buy/do to fix the problem
Most likely your fuel level sender has gone bad. This is a common problem on these cars. What usually happens is that the fuel level sender gets an open in the circuit. An open makes it have infinite resistance which causes the gauge to always read above the full mark. You can get a new sender from Ford or several restoration companies have them. You will have to drop the fuel tank in order to replace the sending unit. You might want to go ahead and replace the fuel pump while you are there.
I'm dropping my tank this weekend with plans to make sure the strainer is not clogged and to change my fuel-sending unit. Does part places like Advance NOT carry the sending units...not wanting to go through Ford! I plan on a blower later on down the road so I don't want to have to buy two fuel pumps.
I don't think you can get them from a regular auto parts store. Its usually a special order item even if they can get it. 5.0 Restoration Supply sells them. Here is the link: http://www.latemodelrestoration.com/iwwida.pvx?;item?item_no=LRS-9275B 1&comp=LRS
If you plan on going boosted down the road, you might as well get the 255 LPH fuel pump now that way you don't have to do it later.
No, the car should still run just fine as long as your fuel pressure is set correctly and your regulator works. All you are doing is flowing more fuel to the rails. Since there is a fuel return line, you will just flow the extra fuel back to the tank.