What was found
WHILE CLIMBING FROM FL330, THE NR 4 ENGINE PARAMETERS BEGAN TO FLUCTUATE AND WOULD NOT RESPOND TO POWER LEVER INPUTS. THE ENGINE WAS SHUT DOWN. THE ENGINE RESTARTED AT FL290 WITH ALL INDICATIONS NORMAL. THE AIRCRAFT RETURNED TO NRT, DUMPED FUEL, AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED THE ENGINE INLET AND EXHAUST, CHIP DETECTORS, AND FUEL PUMP PRESSURE ALL WITH NO TROUBLE FOUND. THE TT2 SENSOR WAS REPLACED AND ALL INDICATIONS WERE NORMAL DURING ENGINE RUN. EXACT PART CAUSING PROBLEM TO BE DETERMINED.