Fuel gauge issue
 

I filled up the Jeep to 3/4 of a tank the other day and I noticed the gauge was stuck. The gauge then started acting funny moving up and down from 3/4 of a tank to full down to empty. After a few days of driving The gauge has come down and appears to be working fine, but I don't know if I can trust the reading. Could this be a bad instrument cluster or a bad sender sensor?

Im having a similar problem. I have a 99 and sometimes when i start mine the gauge will say empty even if its full, then go up and down. If i restart it, it will usually go back to normal... But same here, not sure if i can trust it.

I have the whole "my gas gauge goes down when i go up hill" problem.

and it goes up when I go down?

New sending unit would fix this or is this a common occurance? I had an '87 El camino that had the same fuel shenanigans.

For starters, the el camino did it cuz it's a chevy. Almost all chevy's do that when accelerating and slowing down. It's just how the floater sits. Alot of GM's in general do it. Anyways, I'm having similar problems in my 96 Country. The gauges is stuck at 3/4 of a tank. Doesn't move AT ALL. I'm hoping I don't have to put a whole new pump in. Any tips/advise would be great!

your gas guage runs off ohm readings, resistance, inside the tank there is a bar with wire wrapped around it and a contact that moves in conjunction with the float. they are a bit of a pain to get to especially if there is any significant fuel in the tank. That being said the fuel pickup is in the front top of the tank, and the connections are right there and exposed. My first suggestion would be to check these, as they are exposed to everything and as it corrodes the resistance increases causing poor signal to the gauge. On my truck i smashed the tank on a very big rock and crushed the pickup tube and dislodged the wires for the pump. While I had the sending unit out I took the time to clean all the contacts on the float, brake clean and a pencil eraser and that really helped my readings. but honestly it's a bit of work to drop the tank, remove the sending unit, clean it and reinstall just to have it not work, so unless you already need to drop the tank, or are really cheap (like me) I'd just buy a new setup once you determine that the problem is in the tank