What was found
(CAN) DURING CRUISE FLT CREW NOTICED RT ENGINE EGT, TORQUE & FUEL FLOW STARTING TO SURGE AS WELL AS NOTICING A CORRESPONDING INCREASE, DECREASE IN ENGINE POWER. ENGINE WAS ALSO FUEL LIMITED DURING CRUISE PORTION OF FLIGHT. SURGING WAS CONTROLLABLE AND DID NOT REQUIRE ANY MAJOR ACTION. UPON DECENT, PULLING BACK THROTTLE RESULTED IN A MOMENTARY INCREASE IN ENG POWER & THEN STARTED DECREASING NORMALLY. PRIOR TO TAKEOFF & CLIMB WERE ALL NORM, CREW STATED THAT ENG FUNCTIONED NORM WITH GOOD POWER FOR TAKEOFF. LANDING WAS CARRIED OUT NORMALLY WITH NO PROBLEMS REPORTED FROM CREW. INSPECTION OF ENG & CONTROLS REVEALED NO PROBLEMS. FCU WAS REPLACED, TEST FLIGHT CARRIED OUT.