What was found
AIRCRAFT RETURNED TO PLATFORM, LT ENGINE WAS SHUTDOWN AND (FUEL CONT) AND (SPAR VALVE) LIGHTS TURNED ON. STATUS DISPLAY MESSAGES, APU PERFORMANCE AND ABNORMAL STATUS WERE CHECKED, ALL CORRECT. LT SPAR FUEL SHUTOFF VALVE WAS OPERATED MANUALLY AND IT WAS WITH FAILURE. START ENGINE WAS PERFORMED AND (SPAR VALVE) LIGHT CONTINUED ON. SPAR VALVE WAS REPLACED IAW MM 28-22-11 AND TESTED IAW MM 71-00-00, ALL CORRECT.