CRJ-200 Captain and First Officer report the left engine thrust lever jammed at full thrust 95% during climb. An emergency was declared and the crew executed a single engine landing.

Narrative

At top of climb out of ZZZ; left thrust lever was discovered to be jammed at full thrust (95.0% N1). Friction lock was adjusted with no improvement. Consulted with mechanics on board; Dispatch; and Maintenance Control. Emergency declared; and complied with jammed thrust lever QRH procedure; resulting in securing the left engine. Executed single engine ILS to ZZZ1. Completed rest of flight without incident. Supplemental information from ACN 827239: A certain component in the engine broke and mechanically jammed the left thrust lever.Callback conversation with Reporter 827238 revealed the following information: Reporter stated the CRJ-200 just came out of maintenance the night before. One of the Mechanics onboard the flight; mentioned he thought he knew what the problem might be; having previously experienced a similar event during an engine run. Reporter stated; after they had landed; the same Mechanic opened up #1 engine and later told him the upper cowling hold open rod; or a 'J' hook latch installation bolt; if incorrectly installed; will allow forward movement of throttle; but will jam and prevent any aft movement; or retarding of the throttle.Callback conversation with Reporter 827239 revealed the following information: Reporter stated they tried to push the thrust lever aft; but the throttle would spring forward; back to the 95.0 % forward thrust position. Their QRH procedure calls for shutting down the uncontrolled engine and performing a single engine landing. He doesn't recall seeing any EICAS messages or warnings regarding the left engine performance.