As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON SHUTDOWN OF NR 2 ENGINE, EXCESSIVE SMOKE COMING OUT OF INLET AND EXHAUST AREAS. MAINTENANCE FOUND FUEL CONTROL SWITCH FAILED INTERNALLY. SWITCH WAS KEEPING POWER ON THE 'VALVE OPEN' CONTACTS AT ALL TIMES CAUSING ENGINE VALVE TO CYCLE OPEN AND CLOSE. (M)