What was found
(CAN) (DIVERTED, WITH ENGINE PROBLEMS, CREW CALLED WHEN ON GROUND. ON APPROACH, THE LT ENGINE WOULD NOT IDLE BACK BELOW 79 PERCENT N1. IT WOULD RESPOND TO INPUTS ABOVE 79 PERCENT. CREW ELECTED TO SHUTDOWN THE ENGINE, AND DIVERT.) MX WAS UNABLE TO DUPLICATE THIS PROBLEM, WHILE INITIATING START, N1 RAN AWAY SHORTLY AFTER LIGHT OFF. MX REPLACED FCU. (TC NR 20070104002)