What was found
(CAN) DURING A FLIGHT AFTER MAINTENANCE, AIRCRAFT WAS IN CLIMB TO FL330 WHEN THROTTLES WERE PULLED BACK. CREW WAS UNABLE TO RETARD LT ENGINE THROTTLE. AIRCRAFT DESCENDED TO FL100 WHERE AN EMERGENCY WAS DECLARED AND THE LT ENGINE FIRE SHUTOFF, PBA WAS PUSHED. AN UNEVENTFUL LANDING WAS MADE. MAINTENANCE FOUND THE UPPER COWL SUPPORT STRUT NOT SECURED AND FOULING THE FUEL CONTROL UNIT LEVER ARM. THE AIRCRAFT THROTTLE SYSTEM WAS CHECKED FOR DAMAGE. AIRCRAFT RETURNED TO SERVICE.