As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 1071. LEFT ENGINE INDICATIONS (ALL) FLUCTUATING, ENGINE SURGING. THE FLIGHT RETURNED TO PHL AND LANDED WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS PLACED ON MEL. REMOVED AND REPLACED LEFT ENGINE EPR TRANSMITTER. RAN ENGINE AND BITE CHECKED EEC. NO DEFECTS NOTED.