What was found
RIGHT ENGINE FUEL FLOW AND EPR GAUGES STARTED SURGING PASSING THROUGH FL330 ON CLIMB. CREW ALSO FELT RIGHT ENGINE SURGING. FLIGHT DECENDED TO FL250 AND ENGINE RETURNED TO NORMAL INDICATIONS. FLIGHT RETURNED TO SFO WITH EQUIPMENT STANDING BY. *S/D* ENGINE WAS REPLACED DUE TO SURGING. DURING REPAIR AS ORDER NUMBER D345, IT WAS REPAIRED PER SFOEP FIX LETTER. ACCOMPLISHMENT WAS TO CHECK VSV AND 2.5 SYSTEMS. REMOVED THE FUEL CONTROL AND THE 14 STG CONVERTER VALVE. INVESTIGATIVE FINDINGS FOUND 6TH STG HPC VANES OUT OF RIG / SCHEDULE. THE 2.5 BLEED OUT OF RIG OPEN, AND THE BLEED RING AFT SEAL WORN AND LEAKING DUE TO AIR EROSION FROM BEING MISRIGGED.