What was found
AFTER SHUTTING DOWN THE NR 1 ENGINE FOR A FUNCTIONAL CHECK. FUEL FLOW EGT AND N2 PROGRESSED NORMAL DURING START, BUT THE N1 WOULD NOT ADVANCE PAST 28%. ADVANCING THROTTLE DID NOT CHANGE ANY NR 1 ENGINE PARAMETERS UNTIL REACHING 10,000 FT, AT WHICH TIME THE THROTTLE ADVANCE CAUSED N1 TO ACCERLATE AND RESPOND NORMALLY. FL230 SPEED 230 KNOTS N1=28, EGT-400, N2-56.4, FUEL FLOW 530. REMOVED AND REPLACED THE NR 1 ENGINE MEC IAW AMM 73-20-01-2, ADJUSTED IAW AMM 71-00-00-5, RAN ENGINE IAW JRH 5-7, LEAK AND OPS CHECKED GOOD IAW JRH 7-7.