2000 Infiniti I30 Gas gauge Malfunction

[Apparitions7]

2000 Infiniti I30, 107k

Hi there, Everytime I fill up my tank the needle goes to a little past full. However, when I hit the road for a few days, the needle stops at 3/4 full all the time. It is frustrating because I have to rely on how many miles I go before i decide to fill up again. I am wondering if anyone knows if there is some sort of cleaner I can pour into the gas tank that can clean out the inside of the tank. I have been told by a few other people that the inside of my gas tank could be junked up preventing my car to properly read the amount of gas in the tank. Does anyone have any suggestions on any fluids I can put into the tank that could clean it out?

I have searched through the site but no threads could help me with my problem. If I have missed a related thread I am sorry. Any help would be greatly appreciated.

Thanks alot!

[allensteiner]

pull out the water pump and see if you have a sticky floater maybe?