My 98 Eldorado ETC has been acting up intermittantly for a couple of weeks. This occurs no matter the level of the fuel in the tank. The needle on the gauge will suddenly swing down toward 0 and the chime rings. After a second it climbs back up to the fuel level it previously showed. Then within a few seconds will do the same, needle down and chime then back up. It may do this for a few seconds, or a few minutes. Then it stops and every thing is OK. Just yesterday it started just before my wife filled up (guage was at the 1/4 full mark). After filling up it continued cycling up and down with the chime, up and down with the chime, all the way home, about 15 minutes. Anybody have any ideas? I havent a clue where to start looking unless it's a fuel level sensor in the fuel tank going bad. Any help is appreciated.