fuel gage stops working, then starts working agter time. why is this happening?

Needs a fuel sender this model has a (cartridge) type fuel sender /pump and is a bit spendy aftermarket pumps are NOT recommended will cause runablity issues stalling, misfire, check engine light.and the need to be done several times. (No one wants that headache)

I have the same issue on my 1998 JGC 5.9 limited. The gas gauge needle will go from a little under 3/4 full to empty then back. To change the fuel sender you have to drop the tank. Too much of a pain in the neck for me. I just reset my trip mileage when I fuel up and use that as a more accurate gauge. I also treat my gas with injector cleaner periodically and it seems to help with the gauge issue as well.

I had the same issue with my 2006 GC Laredo 4x4 3.7L. Changed the fuel sending unit since there is 112K on it, and got nothing. Performed all the fuse checks, resets, and everything else I could think of. Finally took the time to trace wires from tank to cluster. Found the problem in the first 20 minutes. I did drop the tank just enough to get a good grip on the harness at the sending unit. After a few ohms checks, I had one wire with no draw. The blue wire is the gauge wire. It had a burned out section about an inch back. The only way I found this is because I removed the harness from the tank to the first connection, its about a 15" pigtail that plugs into the main harness on the body above the axle. Did some not so fancy 12v wire checks off the battery to determine open wire. Took my time and soldered a new piece of wire to connect the two. LOW AND BEHOLD I HAVE A READING GAUGE!!!!!