What was found
APU FAIL AFTER APU START ATTEMPT. SHORTLY AFTER, ODOR OF UNBURNED FUEL PRESENT IN FLIGHT DECK. FUEL FOUND LEAKING OUT OF APU CLAMSHELL DOORS. FOUND MULTIPLE INSTANCES OF FAULT 54-2, IGNITOR PLUG A AND IGNITOR PLUG B LOGGED IN CDS. INPSECTED PLUGS IAW AMM TASK 49-40-04-210-801. BOTH IGNITORS REQUIRE REPLACEMENT. REPLACED BOTH IGNITORS IAW TASKS 49-40-04-000-801 AND 49-40-04-400-801. OPS TESTS GOOD. C/W MULTIPLE APU STARTS WITHOUT DEFECT. THIS CLEARS MEL. RETURNED TO SERVICE.