What was found
AIR RETURN AFTER V1 ON THE TAKEOFF ROLL, NR 1 ENGINE THRUST DROPPED TO 1.44 EPR 79 PERCENT N1, 420 EGT 86.5 N1, 4400 FUEL FLOW STAYED THERE REGARDLESS OF THROTTLE POSITION. REMOVED AND REPLACED FUEL PUMP IAW 73-10-1, OPS CHECKED GOOD ON ENGINE RUN.