thats not really an "idle screw" liike in a carbed car, its a throttle posistion sensor adjustment screw. Go on rx7club.com, and find out how to adjust it properly, as i own a 1st gen, and dont have to deal with it. But i recall needing a test light that you make yourself, pretty simple, all you need is a few wires & like 2 led builbs...any way should all be on rxyclub.