My car does stuff like this too. If i fill it all the way, Itll read an empty tank or bounce back and forth for at least 3 or 4 days. And then next time i drive itll be at half or below. The when it gets low (>1/4) Itll stay whereever till the ignition is turned off. Then when its back on it moves to where it is supposed to be. But if i fill it to like 3/4 its fine and doesnt do anthing unusual. Does anyone think this is a gauge or the sending unit? Im trying to get everything fixed before i sell it
