Turned FJ on today fuel guage was reading fine with 1/4 tank full. Turned off guage went to empty like normal. Started back up a few minutes later and the needle went to past full position. When I turn off the needle slowly goes back to empty….confirmed fuel level in tank and it was at 1/4 full. Would this be a guage that has gone bad or would this be a sender issue and need replacement? Thanks for all the help.