NDDan
Guest
I'd lean toward senders. Make sure cylinder sender is close to all the legs on disk and is lined up good so it can tell when it is in register with steel legs as they go by. The varible resister within the fuel level sender is likely wearing thin and or making poor connection if eratic. If it isn't contantly stuck one way or the other I think quickest easiest with minimum troubleshooting would be replace the sender.