What was found
LAX - LT ENG TORQUE SURGE PLUS OR MINUS 6 TO 7 PERCENT REPORTED AT 60 PERCENT TORQUE AFTER DEPARTURE. A/C RETURNED TO STA W/O INCIDENT. MX DEFERRED LT ENG SRL AND TTL SYS'S. UNABLE TO DUP TORQUE SURGE DURING GROUND RUN WITH SRL AND TTL OFF. A/C RETURNED TO SERV. PROBLEM REOCCURRED ON SUBSEQUENT DEPART. A/C RETURNED TO STATION. MX SWAPPED TO BRIDGE 2 OF TORQUE RING. ACCOMP DELTA P/P CHECK. UNABLE TO DUPLICATE DISCREPANCY. A/C RETURNED TO SERVICE. (M)