I have a Holley 4779 750cfm. My question is: the four screws in each corner, what do they control? Air or fuel, the reason i ask is my car blows out soot and moisture at idle and you cant stay in the garage after 5 min cause the rich fuel smell will burn your eyes. I have adjusted the screws almost all the way in and it it still rich.

Your carb has 4 corner idle set screws. See attached drawing for adjustment procedure. I thought this would be easier to explain. Although I would also check you float level as well. If your float bowl level id too high it can have a similar effect. The fuel level should be just at the bottom of the site plug on the side of the fuel bowl.

http://i25.photobucket.com/albums/c87/HarleyD67/Smilies/idle.jpg

Holley's what a needless pain in the neck

I suspect that the secondary stop nut is set too high, so it is idling on the seconary main jets rather than on the idle curuits....close the sec butterflies a little till u get the mixture screws correct at about 1 1/2 turns.

If the seconadry stop screw is to far closed the opposite effect will happen

I have a Holley 4779 750cfm. My question is: the four screws in each corner, what do they control? Air or fuel, the reason i ask is my car blows out soot and moisture at idle and you cant stay in the garage after 5 min cause the rich fuel smell will burn your eyes. I have adjusted the screws almost all the way in and it it still rich.

Ever had a backfire? It sounds like your power valve is open at idle. What is your idle vacuum and does it match your power valve?