THE PLT REFUELED THE ACFT AT PRINCETON, NJ, BFR DEPARTING ON A FLT TO LINDEN, NJ, THEN CONTINUED ON TO LAUREL, MD. HE BELIEVED THAT HE HAD POSITIONED THE FUEL SELECTOR TO THE RGT FUEL TANK & SAID THAT HE HAD USED FUEL OUT OF THE SAME TANK UNTIL HE ARRIVED AT LAUREL. AT LAUREL, THE PLT POSITIONED THE FUEL SELECTOR TO THE LEFT TANK, WHICH HE BELIEVED WAS FULL. HE THEN DEPARTED ON A RETURN FLT TO PRINCETON. AS THE ACFT WAS CLIMBING THRU ABOUT 6000', THE ENG LOST POWER. THE PLT DIVERTED TO THE BALTIMORE-WASHINGTON ARPT, BUT DID NOT USE THE EMERGENCY PROCEDURE TO RESTART THE ENG. HE ARRIVED OVER THE ARPT AT A RELATIVELY HIGH ALT & ELECTED TO CIRCLE TWICE TO DSCND. HOWEVER, HE LOST TOO MUCH ALT & DRG THE FINAL APCH, HE WAS UNABLE TO REACH THE RWY. SUBSEQUENTLY, THE ACFT HIT APCH LIGHTS ABOUT 200' SHORT OF THE RWY. AN EXAM REVEALED THE LEFT FUEL TANK WAS EMPTY, THE RIGHT TANK WAS FULL & THE FUEL SELECTOR WAS POSITIONED TO THE EMPTY TANK. THE FUEL SELECTOR FUNCTIONED NORMALLY DRG AN OPNL CHECK.