ACR MLG ENG FIRE TAXIING OUT AT MDW.

Narrative

FLT PUSHED OFF GATE ON TIME. #2 ENG WAS STARTED AND THE AFTER START 1 ENG FLOW WAS STARTED BY THE FO. SEEING THAT WE WERE #1 FOR TKOF; OUR RWY WAS 4R AND COULD SEE THAT WE WOULD BE #1 FROM THE TERMINAL RAMP; I ELECTED TO START OUR #1 ENG. I WAS BUSY WITH THE PUSHBACK CREW AND AS PER COMPANY PROCS THE FO ATTEMPTED TO START #1 ENG. THE START ATTEMPT RESULTED IN NO LIGHT-OFF. DUE TO THE FACT THAT I SUSPECTED THE IGNITION WAS NOT ON I ELECTED TO TAXI AND PURGE THE ENG; MOTOR FOR 90 SECONDS; WHILE IN RTE TO THE RWY. THE ENG WAS PURGED WHILE ENRTE TO 4R AND A SECOND ATTEMPT TO START THE ENG RESULTED IN AN IMPENDING HOT START. THE START WAS ABORTED. LATER WE WERE ADVISED TO COME UP ON COMPANY FREQ. WE WERE THEN ADVISED BY A COMPANY CREW TAXIING BEHIND US THAT WE HAD A FIRE IN THE TAIL PIPE OF OUR #1 ENG. MY FO WAS ADVISED TO START OR ENGAGE THE #1 STARTER WHILE I ADVISED MY CABIN CREW OF A POSSIBLE EVAC. THE STARTER HAD BEEN RELEASED AS THE FO WAS CONCERNED ABOUT THE STARTER ENGAGEMENT TIME LIMIT. THE FIRE FAILED TO BE EXTINGUISHED AND THE STARTER WAS AGAIN ENGAGED. LATER THE ARPT FIRE EQUIP ARRIVED AND I WAS TOLD BY THE FIRE CHIEF TO SHUT DOWN OUR OTHER ENG AND GET THE PEOPLE OFF THE ACFT. THE FIRE WAS EXTINGUISHED BY THE FIRE DEPT. I ELECTED TO USE ONLY THE FRONT ENTRANCE DOOR AND STAIRS TO EVAC THE PAX. THE ENG SUSTAINED FIRE DAMAGE AND HAD TO BE REMOVED FOR REPAIR. IT IS MY BELIEF THAT THE REASON WE HAD AN ENG FIRE IS THAT THE ENG WAS ATTEMPTED TO BE STARTED WITH THE IGNITION SWITCH OFF WHICH RESULTED IN A WET ENG. THE FO; OUT OF HABIT I SUSPECT; AS I DID NOT SEE THIS MYSELF AS I WAS TAXIING THE ACFT; TURNED ON THE FUEL LEVER AS HE WAS MOTORING THE ENG WHICH RESULTED IN AN EXCESSIVE AMOUNT OF FUEL IN THE TAIL SECTION WHEN THE START ATTEMPT WAS MADE. I BELIEVE THAT UNDER THESE CIRCUMSTANCES BOTH PLTS SHOULD MONITOR THE PROC OF A SECOND ATTEMPTED START WHICH I ELECTED NOT TO DO AS MY FO HAD BEEN ON THE ACFT MORE THAN 1 YR AND I WAS DEPENDING ON HIM ALONG TO PURGE AND RESTART THE ENG. HE ADMITTED TO ME THAT HE THOUGHT HE HAD MADE THE MISTAKE OF HAVING THE FUEL LEVER UP DURING THE PURGE ATTEMPT BUT WAS NOT SURE. I SUSPECT THAT THIS IS WHAT HAPPENED AND HAD COMPANY START PROCS REQUIRED BOTH PLTS TO MONITOR A SECOND START ATTEMPT THIS MAY NOT HAVE OCCURRED.