ERRATIC FUEL FLOW FOLLOWED BY ENG FAILURE ON SWITCHING TANKS.

Narrative

A THOROUGH PREFLT WAS CONDUCTED AT WMC AND TKOF; CLB WERE UNEVENTFUL. AFTER LEVELING OFF AT FL250 ACFT WAS CONFIGURED FOR CRUISE. APPROX 1 HR INTO FLT L ENG SHOWED EVIDENCE OF VAPOR LOCK; FUEL CONTAMINATION BY ERRATIC FUEL FLOW. BOOST PUMPS WERE PLACED IN LOW POS. AT THIS TIME; THE AUX TANKS WERE BEING USED. AFTER ABOUT 5 MIN AND SEVERAL INDICATIONS OF ERRATIC FUEL FLOW ON L ENG; THE MAIN TANKS WERE SELECTED; L FIRST. UPON SELECTION OF R MAIN TANK THE R ENG QUIT. OUTSIDE AIR TEMP -- 30 DEGS C. ADVANCED MIXTURES SLIGHTLY. DOUBLE CHKED BOOST PUMPS LOW. CALLED CTR ADVISED THEM OF SIT. UPON DSNDING THRU 23500 EMER WAS DECLARED AND ATTEMPTED TO FEATHER PROP. PROP DID NOT FEATHER. DOUBLE CHKED CTL WAS PAST DETENT CONFIRMED. WHILE DSNDING THROUGH APPROX FL180 WITH PROP WINDMILLING AND ALL SWITCHES STILL ON ENG STARTED OUTSIDE AIR TEMP APPROX -20 DEGS C. LEVELED AT 16000 FT AND CONTINUED FLT TO SDL BASED ON RPTS OF WX CONDITIONS AT ALTERNATES ALONG RTE. FLT WAS COMPLETED WITHOUT FURTHER INCIDENT EXCEPT FAILURE OF RNAV EQUIP. SUSPECT ICING OF FUEL SYS CAUSED ENG FAILURE ALTHOUGH NO WATER WAS OBSERVED IN PREFLT. TEMP CONDITIONS AT TIME OF PREFLT APPROX 31 DEGS F. NOTE: FEATHER CHK CONDUCTED IN RUNUP CHKED NORMAL.