1992 taurus 3.8 running bad

alright where to start : these are the things ive changed : maf, cap, rotor, plugs , wires, egr ,iac, fuel pump/strainer, filter, tp sensor, pcv valve, I think some one has been adjusting the idle screw thats by the throttle linkage you know the one that your not supposed to adjust....well it looks like someone has cranked it way in is there a way to set this back to the factory setting the car runs good going down the road just awhat seems to be a low rough idle .... also checked for vacume leaks and i didnt find anything

spayed down thrrottle body with carb cleaner it helped but still rrough idle...