What was found
THE LT ENGINE BEGAN TO SURGE ON NIGHT CROSS-COUNTRY TRAINING FLIGHT. AFTER CHECKING THE ENGINE, MFG WAS CONTACTED AND SAID THEY HAVE HAD SEVERAL REPORTS OF THIS SAME THING HAPPENING. THERE IS ARCING BETWEEN THE MALE PINS ON THE VALVE AND THE FEMALE CONNECTION ON THE HARNESS, CAUSING A CHANGE IN RESISTANCE THAT CAUSES THE VALVE TO DUMP THE PRESSURE IN THE PROP. THE PROP GOES TO FEATHER. THE PROPORTIONAL PRESSURE REDUCING VALVE WAS REMOVED AND A NEW ONE INSTALLED. ENGINE WAS RUN-UP AND CHECKED, OK. (K)