I was wondering what the screw on the face of the TB is? When I unscrew it, it sounds as if my engine is receiving more air, is that correct? Unfortunately I've lost my helms and I couldn't find any diagrams.

How would adjusting this effect my engine?

 

yeah thats your idle adjusting screw. you can adjust the idle of the engine with this. turn it clockwise and it will lower the rpm your car idles at and counter clock wise for higher rpm

 

the one on the face of the throttle body i used that one to get rid of an idle fluctuation