What was found
READ AIRCRAFT DATA CARD. VERIFIED ISSUE WITH THE LEFT ENGINE RPM EXCEEDING 2300. RAN THE LEFT ENGINE AND ATTEMPTED ECU SELF TEST. LEFT ENGINE FAILED SELF TEST. PROPELLER GOVERNOR WOULD NOT CYCLE. REPLACED THE LEFT ENGINE PROPELLER GOVERNOR, GASKET, AND ATTACHING HARDWARE. PROP GOV P/N OFF P-877-16 S/N OFF 16G025-H/G. INSTALLED PROP GOV P/N ON P-877-16 S/N ON 15G365-H/G. PERFORMED ECU SELF TEST WITH NO FURTHER ISSUES NOTED. STATIC RPM ON THE LEFT ENGINE AT 2270-80 DURING RUNUP. NO OTHER ISSUES NOTED DURING INSPECTION AND ENGINE OPERATION.