What was found
APU WONT START, TRIED 3 TIMES. ACFT GROUNDED. PERFORMED APU BITE IAW FIM 49-60, TASK 801. APU HAS FAULT MSG 49-41011 NO FLAME SHUTDOWN. COMPLIED WITH FIM TASK 49-40 TASK 802, CDS REPORTS NO FLAME LAST THREE STARTS AS RECOMMENDED BY FIM TASK. REMOVED AND REPLACED IGNITER PLUG, IGNITER LEAD, AND IGNITION UNIT. IAW AMM TASKS 49-41-51, 49-41-52, AND 49-41-31. GROUND VERIFICATION SUCCESSFUL IAW AMM 49-11-00. RAN APU THREE TIMES NO DEFECTS NOTED. NO FAULTS FOUND.