preacher putz

Fuel pump went bad (96/auto) after replacing the car ran fine, but the fuel guage is way off. Full tank should read about 350 miles,
it only reads about 275
Almost empty only will take about 11 gallons of gas.

So tried another new fuel pump, the same thing. Tried disconnecting the battery, Still seems way off. Anyone have any ideas???

tks preacher putz

PS These were complete assemblies of pump and fuel guage

confab

Is the resistance correct?

Are they touching the bottom of the tank at the end of their range, and does the gauge correspond to that?

If not, perhaps they became bent during assembly or shipping?

billschroeder5842

If you only replaced the fuel pump then there are really two options; your arm is bent or your sending unit was disturbed enough during install to read wonky.

If it were me, I'd take out the unit and bench test the movement of the arm in relationhsip to your gas gauge. Move it slowly as it needs a moent r two to pick up a reading. a bend here or therre may make a difference.

If that does not work, you may have to take apart the sending unit to clean it. I've done it several times and it is not that hard. The big think it to clean the contact point and gentely (gently) clean the wire coils. Clean with WD40 and a cotton ball wiping with the wire direction. Never use sand paper.

ctmccloskey

It sounds like you might have a problem with your ground that works with your gas gauge. If the unit does not have a "Good Ground" then the gauge will read incorrect information. As I recall the wires going to the fuel pump on my 1988 Coupe had three wires, Black, Purple and Red. The fuel pump gets 12 volts from the Red wire, the purple wire is the fuel gauge wire and then the last wire is the (0 volts) ground for the pump.

I also found a ground wire attached to the fuel tank directly on my car.

There are several grounds that have an effect in this part of the car. Check the ground strap on the drivers side behind the door where it grounds the area around the power antenna. When my antenna was acting up the I saw a broken ground strap, after replacing it the antenna and other things started working properly.

Good Luck and I hope you find an easy fix!

P.S. If you want to clean the contacts on the fuel sending unit use a pencil eraser. It is a gentle way of cleaning any electrical connector.

vader86

Take the assembly out and inspect the purple wire, that is the gauge sender wire. Make sure its properly connected to the level. If it comes loose completely the gauge will probably read full tank all the time. It may also have a poor ground and may be time to replace the connectors unless you bought that all as one piece, in which case the ground is faulty somewhere else.

Also make sure you didn't bend the lever arm at all and that it sits into the tray correctly.