What was found
APU ALTITUDE NO START. APU HANGS BETWEEN 0-22 PERCENT DURING START. 0 EGT 23 PERCENT RPM IAW APU COLD START PROCEDURE. REPLACED APU BATTERY. REQUIRES APU HIGH ALT START BEFORE ACFT CAN BE ETOPS. APU ALTITUDE NO START. APU ROTATES BUT NO EGT INDICATIONS DURING START NEED TO T-S AND RPR. R & R P2 INLET SENSOR. APU IN-FLT START FAILED AGAIN 3X. REPLACED IGNITION EXCITER AND IGNITER PLUG. DID NOT REPLACE IGNITER CABLE DUE TO NO STOCK IN BOS. OPS CK'D GOOD. INBD CREW ACCMP'D SUCCESSFUL ALTITUDE START.