What was found
GEG - APU FAILED TO START AFTER 2 START ATTEMPTS. ON SECOND START ATTEMPT, GROUND PERSONNEL NOTICED A LOT OF SMOKE COMING OUT OF APU EXHAUST. PLACED ON MEL 49-00-1. RETURNED TO SERVICE. 2/16 REMOVED BOTH IGNITER PLUGS AND INSTALLED NEW FROM STOCK IGNITERS IAW AMM TASK 40-40-04-400-801 PER 1-5A. PERFORMED APU PRE START INSPECTION IAW TASK 49-00-00-869-801 SUPPLEMENT HS NR 49-0006 STEPS A (1)-(14). STEP A (13) N/A AS COMBUSTOR DRAIN VALVE IS POST MOD. C/W AMM 49-40-04-400-801 PAR 5 B-D, NO DEFECTS NOTED. NO LEAKS NOTED. RETURNED TO SERVICE.