As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW PERFORMED AIR TURN BACK TO MCO DUE TO A SURGE ON THROTTLE BACK OF THE NR 1 ENGINE. THE EPR AND N1 WERE FLUCTUATING ALSO. CORRECTIVE ACTION: MAINTENANCE DISCOVERED THAT NO EPCS MESSAGES WERE SET. THE MCD AND OIL FILTER WERE BOTH INSPECTED AND NEITHER HAD FINDINGS. PERFORMED BORESCOPE WITH NO FINDINGS. REPLACED THE 14TH STAGE BLEED VALVE AND 14TH STAGE BLEED CONVERTER VALVE. HIGH POWER ENGINE RUNS AND CHECK OUTS GOOD.