Carter AFB adjustments

[00GTP]

Hi all;

Have a '79 F30 with the 318s and Carter AFBs. I need to adjust the idle mixture and speed. The only reference to these adjustments I can find are a simple diagram showing the mixture screws and the speed screw.

I have read somewhere that to adjust the mixture, the screws are turned IN for RICHER, OUT for LEAN. This is opposite to the old Quadrajets I'm used to, so would appreciate any input as to the correct method.

Thanks.

[chucka]

I bought a book ttitled Super Tuning and Modifying CARTER Carburetors a couple of years ago, (by Dave Emanuel) but I'm afraid it hasn't been that helpful to me. The book is very detailed, and might be helpful to a true motor head, but I have trouble understanding it. It has a section in chapter 4 with the the heading TURN, TURN, TURN, but which way. I'll quote a little of it here (Note: the book was originally published in 1983):

Until a few years ago, rotating the idle mixture screw (on just about any caburetor) counter clockwise always meant that more air/fuel mix would be discharged and a richer idle mixture would result. But when the bureaucrats in Washington began increasing their stanglehold on Detroit, carburetor manufacturers found that a new system offered advantages in meeting emissions standards. Some companies incorporated a second air bleed into the idle system, which was adjustable. .... Carburetors incorporating this system are commonly referred to as "reverse idle" models since the engine receives a richer mixture when the screws are turned clockwise. Identificaiton of a reverse idle carburetor is usually facilitated by a special tag containing an arrow indicating the direction that the screw should be turned to obtain a leaner mixture. To further complicate the issue, some reverse idle carburetors are equiped with left hand threaded adjusting screws, so they still may be adjusted by the counterclockwise lean procedure.

This discussion goes on for almost another full page. I don't see any specifics about what you need to do from a practical perspective. I hope you can understand it better than me. Good Luck!

[Dreamer]

Back Each screw out till it reaches the highest idle, then turn them in a 1/2 turn. You should be set.

[00GTP]

Many thanks, guys, appreciate the help!