Sticking fuel gauge needle...

[Ashley James]

I know nothing about the late cars but if they have a float in the
tank operating a potentiometer then it is probable causing the
problem. They tend to stick, especially of the car it left standing
for a time. The best thing is to remove it from the tank and waggle
it up and down to remove any sticktion. Clean out the pot bearings
if necessary.
Ash