What was found
(CAN) DURING CRUISE AT FL 390, NR 2 ENGINE POWER DROPPED SIGNIFICANTLY BELOW OTHER ENGINE. ALL NR 2 ENGINE PARAMETERS WERE BELOW THE OTHER ENGINES. THE NR 2 ENGINE POWER LEVER WAS 2-3 INCHES AHEAD OF THE OTHER THREE, IN TRYING TO STABILIZE POWER. NR 2 ENGINE RECOVERED ON FINAL. POST-FLIGHT, THE NR 2 ENGINE FUEL CONTROL UNIT AND THE HIGH PRESSURE FUEL PUMP WERE REPLACED. THE ENGINE TRIM RUN WAS CARRIED OUT SERVICEABLE.