went to the track and the car was surging at idle. my dad already made a pass and the car was running hot. 190ish. so i thought hmmmmm. let me check the idle mixture screws. they were turned it tight from quick fuel. all the way off. i backed them out one turn and idle fine. now the car runs 160ish. wondering if it would be a bad idea to screw them in alittle more to help the motor build heat at idle, low rpms. good or bad. are they only for idle mixture.