What was found
ON DESCENT INTO HKG, NR 4 ENGINE STAYED IN IDLE WITH NO THROTTLE RESPONSE. APPLIED FUEL HEAT WITH NO HELP. ATTEMPTED RESTART TO RESCHEDULE FUEL. STILL NO RESPONSE. LANDED WITHOUT INCIDENT. MAIN FUEL FILTER CHECKED AND REPLACED IAW MM 73-11-00. ENGINE RUN CARRIED OUT. ALL INDICATIONS NORMAL. THROTTLE CYCLING RESPONSE NORMAL. AIRCRAFT DISPATCHED. NO FURTHER DISCREPANCY NOTED.