If the gas gauge needle in your foxbody Ford Mustang is pegged at full,or suddenly drops from full to half way or empty here are a few things that would cause this problem.
If your sending unit is old and original to the car they do tend to go bad after 10+ years of service.Lets face it the 93 fox is now a 17 year old car. If it's the original fuel sending unit it wouldn't be a bad idea to drop the tank and put a new one in. While the tank is lowered also test the power source to the fuel sending unit to make sure it has 12 volts to it with the ignition on.
While you have the tank out, also replace the gas filler tube rubber grommet on the tank if it's old too.
Fuel Sending Unit At 1A Auto
If you add in a new fuel sending unit and you still have an issue, it may be the gauge itself or, on back of the fuel gauge there's a small ciruit board called a (gas gauge amplifier)or(an anti slosh module) they may still be available from Ford here's a picture of what they look like. I'd replace the board before the gauge.
Here's a link to them at
Late Model Restoration
