loss of power on vauxhall astra 1.9cdti?

my vauxhall vectra 1.9cdti had slight loss of power at low acceleration then power kicked in at 2000 revs. having looked at the engine i noticed the swirl flap control rod had came off. so bought a repair kit and refitted the bar and flaps now work correctly. i then thought to take car for a run which now seems to set off ok at low revs but now has loss of power at high revs.