What was found
(CAN) DURING TAXI FOR TAKEOFF, THE RIGHT HAND ENGINE EXPERIENCED AN UNCOMMANDED INCREASE IN POWER OUTPUT TOWARD MAXIMUM. THE CREW SHUTDOWN THE ENGINE WITH EMERGENCY STOP/FEATHER LEVER. THE ENGINE WAS REMOVED, A NEW FCU WAS INSTALLED, AND THE ENGINE RE-INSTALLED. GROUND RUN AIRCRAFT AND RETURNED TO SERVICE. FCU SENT TO MANUFACTURER FOR REPAIR AND INVESTIGATION. SUBMITTER SUSPECTS INTERNAL FAILURE.