Incident Overview
On the day of the accident, the aircraft was on final approach when the pilot reported that the engine backfired, lost power, and did not respond to throttle movements. The aircraft subsequently crashed.
Maintenance History
The engine had a history of write-ups and work orders addressing fuel pressure fluctuations, rough running, a bad fuel pump, engine dying at idle, and a rich mixture.
Fuel Injection Unit Replacement
On the day of the accident, the fuel injection unit was removed for overhaul and replaced.
Post-Accident Testing
After the accident, the engine was tested and ran, but it became excessively rich. Manual leaning resulted in a significant rise in RPM. Subsequent testing of the fuel injection system revealed that the unit operated erratically and was rich at lower pressures.