I am having some issues with the fuel gauge on my 1989 Mustang Lx 5.0 automatic. Here is my problem if the fuel gauge is below the full markand I shut the car off the fuel gauge will drop and not return to the last spot that it was when i shut the car off. The gauge is sometimes as much as an 1/8 of a tank off sometimes it will go back up to were it was and someimes it wont. Any help would be awesome. Thanks

 

1 - Bad Sender.

2 - Bad gauge

Not a real good way to figure either out except to swap 'em. I'd do the sender, as an '89 is probably 'due', if you will, to have that go out. The gauge is unlikely to be the problem, but there are occasions... probability is the sender.

Means yer droppin' the tank, so run it outta gas, then unstrap it and swap it out.

http://www.cjponyparts.com/fuel-tank...FNSxoCYmfw_wcB

That's an example of the part, and has a lil' video by Bill and the guys, and also installation under that so you can have a look see to see if you wanna do it yourself.

Good luck!

Oh, and welcome to the forums!

 

Try replacing the anti-slosh module on the back of your gauge cluster. That is similar to what mine was doing and it was the last thing I replaced. You can get them on eBay from $25-45 dollars used.