What was found
AIRCRAFT DEPARTED AIRPORT TO PERFORM A FUNCTIONAL TEST FLT, AFTER HEAVY CHECK. ON CLIMBOUT, ACFT DEVELOPED PROBLEMS WITH THE NR 1 ENGINE NACELLE OVERHEAT RUNNING HIGH WHICH INDICATED ON BOTH A AND B DETECTION SYSTEM INDICATORS, ALSO AT THIS TIME A "BURNING ODOR" WAS NOTICED IN THE FLIGHT DECK WITH NO SIGHT OF SMOKE. PILOT REDUCED POWER ON THE NR 1 ENGINE, TEMPERATURE BEGAN TO REDUCE BACK TOWARD "0" (ZERO), WHICH INDICATED ON BOTH A AND B SYSTEMS. THE PILOT DECIDED TO SHUTDOWN NR 1 ENGINE DUE TO THE "BURNING ODOR" CONTINUED, AFTER SHUTDOWN ODOR DISSIPATED. PILOT DECLARED AN EMERGENCY & LANDED WITHOUT INCIDENT. DURING TROUBLESHOOTING NR 1 & 3 PRSOVS, NR 1 & 2 TEMP SENSOR & CONTROLS, NR 1 & 2 IP CHECK VALVES, NR 1 & 2 HIGH-STAGE CHECK VALVES, & NR 1 & 2 PRECOOLERS SWAPPED & LEAK CHECK PERFORMED PER AMM 36-12-01, REV 109. THE OVHT INDICATION STILL EXISTED. AS PER MANUFATURER RECOMMENDATION, NR 1 THREEWAY VALVE INSPECTED & FOUND SMALL POPPET NOT FULLY CLOSED AT 1.25-INCH PORT IN FLT MODE AND BOLT HOLE ON SMALL POPPET WORN. NR 1 AND 2 THREEWAY VALVES & NR 1 & 2 HIGH-STAGE VALVES SWAPPED & LEAK CHECK PERFORMED PER AMM 36-11-06, REV 109. NR 1 & 4 ENGINE RUN AT 1.30 EPR PERFORMED & INDICATION FOUND NORMAL PER AMM 71-22-22, REV 109. A NEW THREEWAY VALVE INSTALLED TO NR 2 ENGINE.