Fuel Gauge

[Logan]

My fuel gauge reads full when I fill it all the way up, but goes rapidly down so that by the time it's down to empty it is actually still about half full.  Does anyone have an idea why it's like this?

[joefrazer]

You have one of two problems...both of which require tank removal to fix. Either the float is sinking or you have the wrong tank unit. A few Jeep units look the same but are calibrated differently. If someone swapped the tank unit at one time, there's a chance that they used the wrong one.
If the unit was going straight to ground, your gauge would read full all of the time, if the unit had a bad ground, it would read half or less all of the time.

[Logan]

Guess I'll have to drop the tank at some point.

[dpledger]

At about 200K miles the float on my 53K fuel sender started taking on gas-proved to be a small hole under where the holder contacts it. Pinhole leak, so came on very gradually.  If you take it out and it sloshes, drill a 1/8" or so hole into the leak so you can drain it. Then solder it shut.