Pontiac Repair: gas guage, haynes repair manual, fuel gauge

Question
Hi todd: On my 1999 pontiac grand am gt 3.4 engine, twice last week (May 19 thru 24, 2008) my fuel gauge indicator went from its normal position (3/4 full) down to the "EMPTY" then back to its normal position in a matter of two or three seconds. I guess its something with the fuel sending unit which appears to be on top of the fuel tank according to the haynes repair manual. This is similar to (though probably not the same)as a problem that i had two years ago. Back then, all the dash instruments and lights would go off for a few seconds then come back on. my mechanic changed the ignition and the problem disappeared. any thoughts on the probable cause of this problem and what it would take to fix it in the garage because i dont to work on anything of this nature. I'm too old and to smart to be working with fuel when i dont know anything about how to fix this kind of problem., thanks, Phil S.

Answer
Hi Phil:
It could be a lot of different things. The fact that it comes and goes means it could be a bad connection somewhere. In one of the connectors between the sensding unti and the engine computer. it could be the gauge it's self. Unsually when the sending unit goes it stays broken or it will only act up when it's less than 1/2 a tank. when happnes to the sending untin it the wiper on the sending unit goes bad. The problem being here is that it doesn't sstay broken which mnakes it hard to test anything. If it stays broken I can tel you what to look for.