As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOTS REPORTED THAT ENGINE THAT THIS FUEL CONTROL UNIT WAS INSTALLED ON COULD NOT BE CONTROLLED BY NORMAL COMPUTER MODE, AND THAT WHEN THEY WENT TO MANUAL MODE THAT THEY COULD NOT CONTROL ENGINE SPEED FUNCTIONS EITHER. IT SEEMS THAT THIS FUEL CONTROL HAS SOME INTERNAL FAULT. REPLACEMENT FUEL CONTROL RESOLVED THIS PROBLEM. (K)