As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LEFT ENGINE POWER FLUCTUATED DURING CLIMB BETWEEN FLIGHT LEVEL 350 TO 390. THE DISCREPANCY WAS CAUSED BY THE FUEL CONTROL UNIT BEING OUT OF ADJUSTMENT. CORRECTIVE ACTION TAKEN WAS TO MECHANICALLY ADJUST THE DECELERATION SCHEDULE OF THE FUEL CONTROL. OPERATIONS CHECK NORMAL.