What was found
VERY LOW DUCT PRESSURE DURING FIRST ENGINE START (RIGHT ENGINE), LONGER THAN NORMAL START PROCESS. TRANSFERRED TO MDDR 117914 IAW MEL 49-11-01-01, CAT "C", DUE 28-SEP-2019. MAINT ACTION C/W. LP 1210156 - M6: REMOVED AND REPLACED THE APU AIR SUPPLY SHUTOFF VALVE IAW AMM 36-11-10. OPS CHECK GOOD AND LEAK CHECK GOOD AT THIS TIME. DMI 117914 REMAINS OPEN DUE TO ENGINE RUN REQUIRED. COULD NOT RUN ENGINE DUE TO GROUND TIME. MCC NOTIFIED. LP 1210161 - M1: C/W DG 49-11-01-01. LOCKED OUT APU BLEED. LP 1210166 - M3: REMOVED AND REPLACED SURGE CONTROL VALVE ON APU IAW AMM 49-53-01. INSTALLED A SERVICEABLE FLOW CONTROL GASKET IAW AMM 49-53-08. OPS CHECK GOOD, COMPLIED WITH MX PROCEDURE. LP 1210168 - M7: PERFORMED ENGINE RUNS AND WATCHED PNEUMATICS DURING ENGINE START WITH ADP OPERATING IN AUTO POSITION IAW AMM 71-00-00. PNEUMATICS PARAMETERS ARE NORMAL. THIS CLEARS MDDR #117914. PLACARDS REMOVED AND MCC NOTIFIED. GASKET OFF PART (PN: 3876179-2, SN: NSN)