A valve adjustment shouldnt effect your idle. Youll just hear the valves ticking at low rpm. As for your idle, what is it doing? Bouncing around? If so, how bad? Is it really low? Really high? Sputtery/cough like? Hows it run above idle? Any recent work done to the car? If not, when did this problem start? Does it do it in all types of weather?
Theres a ton of missing information that makes it impossible to give you any advice at this point.