What was found
YVR - ENGINE FLAMEOUT - DURING C-20 CHECK ENGINE PERFORMANCE DETERIORATION TEST THE NR 2 ENGINE EXPERIENCED IMPENDING FLAME-OUT WITHIN 40 SECONDS OF SHUTTING OFF THE NR 2 FUEL TANK BOOST PUMPS, ENGINE RECOVERED NORMALLY WITH BOOST PUMPS WERE RESELECTED TO THE ON POSITION. NR 1 ENGINE OPERATION WAS NORMAL. MAINTENANCE PERFORMED FUEL FEED SYSTEM VACUUM TEST PER AWA T/C F3L28001, NO LEAKAGE WAS NOTED. REMOVED AND REPLACED FUEL SHUTOFF VALVE RT WING IAW BMM 28-23-11, PG 401. RE-ACCOMPLISHED PERFORMANCE DETERIORATION CHECK PER AWA T/C F3B28001, TEST WAS GOOD.