As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL PRESSURES ARE UNSTABLE AND FLUCTUATING. THE ENGINE DRIVEN FUEL PUMP AND FUEL CONTROLLER ARE REPLACED AND THE PROBLEM SOLVED. SUBMITTER SUGGESTED POSSIBLE CAUSE AS DEFECTIVE PARTS OR ASSEMBLY PROCESS OF THE PUMP AND FUEL CONTROLLER AT RE-MANUFACTURE OF THE ENGINE.