What was found
INFLIGHT SHUT DOWN AND AIR TURNBACK WITH DECLARED EMERGENCY. ON DEPARTURE NR 1 ENGINE EXHAUST WAS DARKER. NR 1 EGT WAS APPROXIMATELY 50 DEG ABOVE NR 2 F FLOW WAS SLIGHTLY HIGHER. ABOVE 10,000FT NR 1 BLEED TRIP OFF CAME ON RAN CHECK LIST, WOULD NOT GO OUT. NR 1 ENGINE OVERHEAT CAME ON. REMOVED AND REPLACED NR 1 ENGINE BLEED AIR REGULATOR, BLEED AIR CHECK VALVE, NR 1 ENG LT CORE FIRE DETECT ASSY, NR 1 ENGINE PNEUMATIC HIGH STAGE PRESSURE REGULATOR, NR 1 ENGINE PNEUMATIC PRSOV, NR 1 ENG HIGH STAGE VALVE PER MM.