emission control causing rough idle?

Dan, I;ve been waiting on your input on this, I followed the method for valve lash adj. described by you, engine running,I have no vacuum leaks,I tested with carb cleaner,one thing you said sparked me... at night when the engine is idling, the lights flicker a bit, may be fire from alt...dont know how to check the other possible probs, you guys' input is always welcomed. Thanks Gary