As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TO BALANCE FUEL IN FLIGHT, LEFT FUEL SELECTOR HANDLE MOVED FROM LEFT MAIN TO RIGHT MAIN. BOTH FUEL BOOST PUMPS REMAINED ON. AFTER FUEL LEVELS BALANCED, LEFT FUEL SELECTOR HANDLE MOVED TO POINT BACK TO LEFT MAIN TANK. LEFT MAIN FUEL INDICATED QUANTITY DECREASED RAPIDLY CAUSED BY UN-COMMANDED CROSSFEED FROM LEFT MAIN TO RIGHT ENGINE. RIGHT MAIN QUANTITY INCREASED. FUEL LEVELS WOULD EQUALIZE OVERNIGHT THROUGH THE CROSSFEED LINES AND FUEL SELECTOR VALVES. SUSPECTED LEFT FUEL SELECTOR VALVE TO BE LEAKING INTERNALLY. BOTH FUEL SELECTOR VALVES AND FUEL CROSSFEED SHUTOFF VALVES OVERHAULED.