ACR LGT HAD TO MAKE MANUAL START OF #3 ENGINE.

Narrative

#3 ENG WOULDN'T START. CONTRACT MAINT STATION SAID APPEARED TO BE BAD START VALVE. MEL SAID GO WITH MANUAL START SENT FOR MECHANIC. AGENT ASSURED ME MECH WOULD BE THERE MOMENTARILY; SO I ELECTED TO LEAVE ENG RUNNING TO SAVE TIME. MECH ARRIVED PRETTY QUICKLY. DIDN'T CHK IN WITH ME. GND MAN SAID HE SEEMED TO BE HAVING TROUBLE WITH COWLING. GOT #3 STARTED; BUT OBVIOUSLY COORD BTWN MECH; GND MAN AND MYSELF WAS POOR. MECH CAME TO SIGN OFF AND CONFIRM VALVE CLOSED. HE HAD BEEN MANUALLY HOLDING VALVE OPEN FOR A WHILE (BLEEDS CLOSED; NOTHING HAPPENED) BEFORE MY SIGNAL TO OPEN IT. I ASKED IF HE NEEDED TO CHK WITH OUR MAIN BASE MAINT TECH PEOPLE AND HE SAID HE DIDN'T. JUST AFTER DEP; I REALIZED WE PROBABLY SHOULD HAVE HAD THE VALVE PLACARDED. ASKED AGENT BY RADIO TO CALL TECH AND SEE IF WE SHOULD RETURN TO GATE FOR PLACARD BY MECH. ADVISED TECH SAID NOT NECESSARY AS LONG AS THEY KNEW ABOUT IT. NEXT LNDG AT MAINT STATION. DIDN'T GET SOME HELPFUL ADVICE/SUGGESTIONS I COULD HAVE USED. HOWEVER; BASIC PROB WAS: TO HANDLE THIS SITUATION PROPERLY; AT CONTRACT MAINT STATION; SHOULD HAVE SHUT DOWN; CALLED TECHNICIAN MYSELF; BRIEFED GND MAN AND MECH. WOULD HAVE SAVED TIME; NOISE; FUEL AND THE NEED FOR THIS RPT.