As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN TROUBLESHOOTING A SNAG FOR A ROUGH ENGINE, IT WAS NOTED THAT THE AIRFRAME ELECTRIC FUEL PUMP DURING LOW RPM WOULD CAUSE THE SYSTEM TO DROP A HALF TO A POUND OF FUEL PRESSURE WHEN IT WAS SWITCHED OFF. THIS WOULD CREATE ISSUES WITH THE FUEL SET UP FOR THE DIAMOND. THE PUMP IS ALSO VERY NOISY WHEN RUNNING. THE COMPANY HAS HAD AT LEAST TWO OTHER OCCURRENCES IN THE LAST YEAR THAT ARE SIMILAR TO THIS.