I have been trying to get my idle right on this 2000 Civic Ex

Its really low and is worse when engine is cold

it Idles around 250-300 rpm

the brakes go to the floor at first as if there is NO vacuum
then Ill have good brakes it idles a little better after warm

around 400-500 rpm

I first found the idle screw had been totally unscrewed and removed
so I located one at a junkyard and screwed it in until the idle went down more
then unscrewed slowly and the highest the idle will go is back to where it was

is there a default idle screw or something the throttle linkage sets against that would raise it ?

 

Ok so i located some adjustment on the intake manifold and got it close.whats the screw in throttle body for? Fine tuning?