What was found
DURING NR 1 ENGINE TEST VIBRATION SURVEY, ENGINE BEGAN TO SURGE AND STALL UNCOMMANDED WHILE APPROACHING 81 PERCENT N1 FOLLOWED BY MASTER CAUTION LIGHT ENGINE INDICATION ON THE 6 PACK FOLLOWED BY LOW OIL PRESSURE INDICATION AND "ENG FAIL" ILLUM PRI ENG DISP ENG IND AND "ENG FAIL" ILLUM PRI ENG DISP. NR 1 ENGINE EEC BITE SHOWS FLT CD 73-10331 "THE FMV DEMAND AND POSITION SIGNALS DISAGREE" FOR LEG 0. PERFORMED INSPECTION OF THE NR 1 ENGINE IAW TASK 71-00-00-210-801 F00, NO DAMAGE NOTED. REPLACED NR 1 ENG HMU REF 73 21 10. LEAK CHECK NR 1 HMU IAW TASK 71-00-00, TEST 3A. LEAK CHECKED GOOD. ACCOMPLISHED ACTUATOR TEST 12 AND ENGINE RUN BITE, EEC BITE CHECK TEST 13 NR DEFECTS NOTED.