fuel guage problem what will repair it?

If it still works SOMETIMES, it's most likely a poor electrical connection........................ The first thing I'd try is to disconnect the electrical connector at the outside of the gas tank and repeatedly push it back in place.That is the connection most liable to be effected by corrosion-especially from road salt. ......................Sometimes just burnishing that connection will do the trick................... IF IT DOES, then clean the pins leading into the tank (if you can get to them) but in any case be sure to put some electrical grease into the fitting after burnishing the connection. That will shield the contacts and prevent more corrosion.