What was found
BTB LEFT ENGINE BLEED OFF EICAS ON CLIMBOUT, WOULD NOT RESET. PER FIM 36-20 F T 804 UP TO BLOCK 36. PERFORMED THUMB TEST, PER AMM 36-11-18. FOUND PRV LOCKOUT PIN LOOSE ALLOWING AIR TO ESCAPE. TIGHTENED LOCKOUT PIN, PER AMM 36-11-18-404-818-001. PERFORMED ENGINE RUN, PER AMM 71-00-00-00. OPERATIONS CHECKED GOOD. LEFT ENGINE SUPPLIED GOOD PRESSURE. PER FIM 36-20 FT 804 AND FIM 36-10 FT 832 BLOCK 21. REMOVED AND REPLACED PRESSURE REGULATING VALVE CONTROLLER, PER AMM 36-11-19. PERFORMED ENGINE RUN, PER AMM 71-00-00. NO HELP, REF LOG PG 1240981 ITEM 1 FOR CORRECTIVE ACTION.