As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TROUBLESHOOTING OF THE NR 1 ENGINE NOT STARTING AND LOW DUCT PRESSURE, FOUND THE NR 1 ENGINE TOOK 20 SECONDS TO SHUTDOWN. NR 1 ENG VALVE LIGHT STAYS ON BRIGHT. ACFT GROUNDED. REMOVED AND REPLACED THE NR 1 ENGINE HMU IAW T/C N8473000, AND T/C N8473001. OPS & LEAK CHECKED GOOD.