Also take a look at fuel gage info at my web site.
Bad grounding can cause irratic behavior. Gage reading high indicated stray resistance in the circuit somewhere. Check all connections for corrosion.
If the gage reads correctly but jumps around a lot due to fuel sloshing in the tank, then the dash unit is bad. Dash unit has silicone fluid which damps the needle.
A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!