As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON SHUTDOWN OF THE LT ENGINE THE CREW REPORTED THE RPM WAS SLOW TO DEGRADE ACCOMPANIED WITH A RISING EGT. THE ENGINE EVENTUALLY SLOWED AND STOPPED WITH EXCESSIVE AMOUNTS OF SMOKE COMING FROM EXHAUST.A SUBSEQUENT INSPECTION REVEALED THAT THE LT FUEL SHUTOFF VALVE HAD FAILED TO CLOSE COMPLETELY WHEN THE STOP BUTTON WAS DEPRESSED, THERE WAS NO DAMAGE TO THE ENGINE AS A RESULT OF THIS INCIDENT. THE FUEL SHUTOFF VALVE WAS REPLACED AND THE AIRCRAFT RETURNED TO SERVICE.