As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW NOW REPORTS ON TAXI OUT, THE LEFT BLEED WILL NOT OPEN, 80 PERCENT N2 ON LEFT ENG AND NO BLEED PRESSURE INDICATED. REPLACED LEFT ENG PRV. PERFORMED HIGH POWER RUN TO CHECK OPERATION OF LT BLEED SYSTEM DUE TO BLEED VALVE NOT OPENING AT IDLE AND AT POWER SETTINGS. HIGH POWER ASSURANCE RUN. CHECKED OK.