What was found
DURING CRUISE AT FL370 FUEL ADVISORY FLASHED WITH RT OUTER & RT INNER QUANTITIES FLASHING. THE LT INNER QTY WAS DECREASING THROUGH 7000 LBS OF FUEL WITH RT INNER QTY AT 13,300 LBS. SUSPECTED FUEL LEAK. RESET FQI CHAN SUPPLY 1 & 2 CB'S WITH NO CHANGES & QTY CONTINING TO DECREASE RAPIDLY. TURNING OFF LT INNER FUEL PUMPS STOPPED THE QTY DECREASING AT 4,300 LBS. CHECKED FOR VISIBLE FUEL LEAK BUT IT WAS TOO DARK. THE QTY REMAINED AT 4,300 LBS UNTIL SHORT FINAL DURING APPROACH WHEN IT BEGAN TO INCREASE. AT BLOCK-IN THE FUEL IN THE LT INNER READ OVER 13,000 LBS. DECLARED AN EMERGENCY. R & R COMPENSATOR IN RT OUTER TANK IAW AMM 28-42-33-04-01.