Dear jd620,

Hope you're well. Gasoline is a hydrocarbon cocktail, amongst which are paraffins, or waxes, and "varnishes", or tar-like molecules. Were it not for detergents in gasoline, these chemicals would quickly coat fuel system tubes and components. When gasoline sits for a long time, paraffins and varnishes settle on fuel system surfaces, including the internals of the fuel tank send unit.

I'd add a 20-ounce bottle of Techron fuel system cleaner to the tank, and fill with fresh fuel. Put in the Techron, before adding the fuel, to ensure good mixing. Allow this to sit for a day or so, and then drive the car, until it needs another fill-up. I'd add a further bottle of Techron, at the next fill-up. Allow this second load of reinforced fuel to rest in the tank for a day or so.

If this does not clean the send unit, to the point that it works again, the unit likely will have to be replaced.

Hope this helps.

Yours faithfully,

Spook