My 84 Z28 has been off the road for a couple years and only started every few months. I never noticed untill this week that the needle was on full (I could'nt recall if I had parked it with a full tank) I had decided to do some needed work to it (brakes, shocks, tune up) and drive it this summer. The car has failed to start this time and when I physicly checked the tank fuel level, I found it to be emty. (gas gage still on full) Well I put in some fuel, about 5 gal or so and the gage then went past the full mark and pegged out (about 1/4 tank level distance)
So, what is likely the culprit here? What can I do to fix this?

 

fuel guage will behave this way when there is a break or severe corrosion somewhere in the wiring between the sender & guage.