ok i did what u said when i tryied startingwith iac disconnected whould stay running till cranked the idle screw. got it to run steady at 500 in park and about 350 in drive. if i crank too much on the screw the motor would start surging. do i need to set to to 450 in park or drive. i noticed i big different when fired back up. alot quiter and smoother barely if tell its running. but im not acheiving 600 in dive with the foot on the brake. sould my engine be surging when setting the min air.