I have a Oldsmobile "Delta 88" 1986 four door front wheel drive, and when I recently changed my fuel pump

my gas gage has stopped working, only thing it does is it goes over to the full mark when I start the car but then it goes back to empty mark when I turn off the car. I would like to know how to fix this problem.I have a Oldsmobile %26quot;Delta 88%26quot; 1986 four door front wheel drive, and when I recently changed my fuel pumpcheck the electrical connection at the pump,did it work before you changed the fuel pump if so something didnt get plugged in right,may require to drop the tank again(ouch).sounds like the sending unit (the float part).I have a Oldsmobile %26quot;Delta 88%26quot; 1986 four door front wheel drive, and when I recently changed my fuel pumpyou most likely have a bad ground connection try grounding one of the metal lines coming off the sending unit to the frame of the carI have a Oldsmobile %26quot;Delta 88%26quot; 1986 four door front wheel drive, and when I recently changed my fuel pumpsounds like you shorted out the wire that goes to the sensor itself. that will bypass the sensor, obviously. you will have to get back under that car and locate the sensor wire and patch the brake or replace the wire entirely.I have a Oldsmobile %26quot;Delta 88%26quot; 1986 four door front wheel drive, and when I recently changed my fuel pumpChances are that somewhere along the line you mistakenly used gasoline with methanol or other additives in it. This probably caused a chemical in both your pump and your sendin unit. Unfortunately, if this has happened, you will probably have to change your fuel sender unit. THe other possibility is that road salt has gotten at your wiring harness under the car and you will have to find and trace back the harness and/or remove corrosion on it. Good Luck!!!