What was found
AFTER LANDING, WHILE AT FLIGHT IDLE THE ENGINE BEGAN TO SURGE, T.O.T. WOULD GO FROM 450C-500C AND N1 WOULD VARY FROM 60-61.5 PERCENT. THE MECHANIC CHECKED THE FUEL SAMPLE, INSPECTED THE EXTERNAL FUEL FILTER, FUEL NOZZLE SCREEN FOR CONTAMINATION, NONE FOUND, REMOVED AND REPLACED THE FUEL CONTROL AND COMPLIED WITH PNEUMATIC CHECK AND AIRCRAFT WAS RETURNED TO SERVICE.