As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING T/O NR 1 ENG ONLY WENT TO 90% N1 NOT 93% ADVANCED THROTTLES AT LEAST 1-1 1/2 KNOB WIDTH WITH NO RESULT, ABORTED T/O AT 60 KNOTS NO RTO. MAINTENANCE ACCOMPLISHED FIM TASK 77-11-00. REPLACED ENG N1 SPEED SENSOR. BITE CHECKED EEC AND DEU, NO FAULTS FOUND. ACCOMPLISHED TEST NR 5 POWER ASSURANCE TEST SATISFACTORY.