Try running a bottle or two of Techron fuel system cleaner into the gas tank. Sometimes a coating will form on the fuel level sensor contacts and affect the level reading. All of the issues I have previously had with erratic fuel level readings have cleared up after a bottle (or two) of Techron. It works well enough that it is noted on the bottle as being effective on some fuel level sensor issues.
Hope this helps,
Gerry G.
Hope this helps,
Gerry G.
