As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
3 HRS INTO FLT LEFT ENG STARTED SURGING LEFT EPR CYCLES. BETWEEN 1. 20 - 1.23 N1 CYCLES WITH THROTTLES RETARDED 80.5 TO 81.8 ALL OTHER ENG PARMETERS CYCLING IN SIMILAR RANGE FLT LEVEL 320 TRYED ALT EEC BUT NO HELP HAD NO EFFECT FUEL FUEL FLOW 4520-4650 STABILIZED AT 13K FEET - REPLACED FUEL METERING UNIT.