What was found
TWO SEPARATE OCCURRENCES OF THE ENGINE 'SURGING' AT FULL POWER WITH LESS THAN 16 GALLONS TOTAL FUEL ON BOARD. COULD NOT DUPLICATE ON THE GROUND. WITH FULL TANKS, COULD NOT DUPLICATE AT NORMAL FLIGHT ATTITUDES. ENTIRE FUEL SYSTEM DISASSEMBLED AND CLEANED, FOUND INSECT NEST AT AFT LEFT FUEL TANK FEED LINE. RESEARCHED LOGS, WINGS WERE REMOVED DUE TO ACCIDENT (5-88), AIRCRAFT WAS REPAIRED AND RETURNED TO SERVICE (1-89). SUSPECT INSECT NEST HAS BEEN THERE SINCE '89. (AIRCRAFT TT AT WING REMOVAL, 3,814.0 HOURS. CURRENT AIRCRAFT TT, 6,800.0 HOURS.