When I pull up at lights in 260Z ( 280 Engine with twin SUs ) the revs always settle at around 1200 rpm. If I blip the throttle slightly this usually re-settles at around 800rpm. Unfortunately it also gets the idiot next to me in an XR3 all excited at the prospect of a race. Any ideas, have checked dashpot oil in carbs plus throttle cable for sticking plus throotle idle screw.