As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING START OF THE NR 4 ENGINE, THE NR 1 START SYSTEM FAILED TO START ENGINE. WHEN CREW ATTEMPTED TO SWITCH TO SYSTEM 2, THE ENGINE FOGGED AND A HOT START OCCURRED INCLUDING MAX EGT. SUBSEQUENTLY CREW PULLED THE FIRE HANDLE AND BOTTLE WAS DISCHARGED. REPLACED THE NR 1 AND NR 2 IGNITION PLUGS, CONDITION MOTOR, AND FIRE BOTTLES. AIRCRAFT RETURNED TO SERVICE.