Hi , sorry to ask again but ive got my Rs running and im setting the idle speed as per the book and my question is this...

Does turning the screw on the throttle body have an IMMEDIATE effect on the idle or is there a slight delay? i can get it ticking over sweet at 900 but when i restart etc.it seems to fall right down to 500. should i be doing 1/4 turns so the e.c.u etc.can catch up or is it possibly something else, as im winding it in it responds but quite slowley it seems.

thanks again for any help