What was found
AFTER T/O AT ABOUT 6000' L/H ENGINE EPR STARTED TO FLUCTUATE ABOUT .05 UP AND DOWN. OIL PRESSURE ALSO FLUCTUATED /- 25 PSI. WE TURNED OFF TAI AND THE ENGINE SEEMED FINE.LESS THEN A MINUTE LATER THE SAME PROBLEM CAME BACK. PULLING THE POWER BACK ON DESCENT BACK TO MSP THE PROBLEM WENT AWAY. THE PROBLEM SEEMED TO BE AT CLIMB POWER OR HIGH POWER SETTINGS ONLY. REMOVED AND REPLACED THE 14TH STAGE CONVERTERPER M/M 71-00-00-5. PERFORMED TEST 6 AND NO PROBLEMS WERE FOUND. PERFORMED HIGH POWER ENGINE RUN FOR 10 MINUTES AT TAKEOFF POWER, PER 757 JRH AND ALL PARAMETERS WERE GOOD WITH NO FLUCUATION OF ENGINE INSTRUMENTS. A/C OK FOR SERVICE. REACTIVAED THE T/R AND STOWED BYPASS PIN. ALL COWLINGS CLOSED AND LATCHED.