As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF LARGE L DUCT PRESS VARIATIONS. HI CABIN TEMP TO 87. HAD TO TURN OFF L PACK TO REG & GAIN CONTROL OF PRESS AND TEMP. TURNED L PACK BACK ON DUCT PRESS STABLE AND TEMP CONTROLLABLE. REPLACED LEFT PRSOV. RAN ENG TO POWER PER JRH, BLEED SYSTEM CHECKS NORMAL, PRESSURE STABLE, PACK OPERATION NORMAL.