Had bad sending unit, so I replaced with Specta Premium SG20A (and threw in a Bosch TPI fuel pump while I was there). Car had about 1-1/2 gallons when sending unit was changed. After change, gauge read just barely above "E." Filled with gas. Started car and still reads "E." It took about 15 minutes of driving for the gauge to S-L-O-W-L-Y creep up to about 7/8. It did the same thing back a few months ago when I filled the tank. Took forever for the gauge to move from "E" to "F." Problem was, it never again moved off "F." So, I figured I need a new sending unit, which I installed yesterday (fortunately, a good friend has a shop with a two-post lift; made the job much easier). Question is: do I have a faulty fuel gauge?

 

Put the rear end up on jack stands so you can get under there. Unplug the body connector that is three wire for the sender unit/fuel pump/ground. Turn the key to ignition on and you should read way past full or infinite resistance. Then back probe the purple connector on the body side and ground it out. If it goes to empty then all of the wiring and the gas gauge is fully functional and your problem lies with the sending unit.