The fuel gauge on my 1998 Oldsmobile Intrique is stuck over the full
mark all the time, even when the ignition is off. The gauge is stuck
over a small peg located just above the full mark. It became stuck
after my father took it in to a mechanic to have it worked on. I think
they replaced the intake manifold, but I’m not sure. Also, before we
took it in to the shop, we unplugged the battery cables on the advice
of a friend who suggested that the system might need to be
"rebooted" in the car. In retrospect, I don’t know what we were
thinking. Anyway, it is a possibility that the gauge might have been
stuck at that time as well; however, it definitely worked before we
unplugged the cables. If you have any information or suggestions about
why it could be doing this, I would be very appreciative!