crx idel

ok my freind had 1990 honda crx si he had a b18 swap well when he would start it it just sat tgher vroooom rrrrrrrrrrrrrrrrrrrrrrrrr.... like when we stop at a light put it into nuetrul it would idel high and also took off realy fast is it bad to turn up your idel i want to do it to a 1993 ls integra b18

idle saves gas money, thats all, and its easier on the engine, bot there are three screws on the intake manifold and tightening them will adjust your idle, atleast i am fairly sure about this, if anyone would back me up