What was found
DURING CRUISE AT FL340, CREW REPORTED ENGINES WERE FLUCTUATING 0.4% N1 FUEL FLOW FROM 2,600 TO 2,630 LBS. ALL GAUGES FLUCTUATING. ENGINES WOULD NOT STAY IN SYNC. PMC ON OR OFF MADE NO DIFFERENCE. AUTOTHROTTLES OFF FLUCTUATED AT 0.6%. DURING A TURN, FLUCTUATION WAS 1.0% N1 AND 2,600 TO 2,700 LBS FUEL FLOW. DIVERTED TO CLT. ON DESCENT AT FL170, OPERATION RETURNED TO NORMAL. MX TROUBLESHOT PER MM 71-00-42 AND FOUND THE NR 1 ENGINE VSV FEEDBACK CABLE BAD. REPLACED CABLE PER MM 75-31-00. RAN ENGINES PER MM 71-00-00 TEST 8, ACCEL/DECEL TEST. OPERATIONAL CHECK NORMAL. ALSO, REPLACED BOTH ENGINE FUEL FILTERS PER MM 73-11-02. NO FUEL OR FUEL FILTER CONTAMINANTS FOUND. RAN ENGINES. NO LEAKS NOTED.