Lean condition, no idle circuit adjustability.

[Nhrajeff]

Hey. Cliff, I just fired up my 79 Trans Am, carb # 17059253. The car runs very poorly, but if I cup the air horn with my hand, it dramatically improves. I've also noticed that regardless of what I do with the idle mixture screws, there is no change. Could you give me a couple of tips on what to look for first. BTW, what float level spec do you suggest? Fuel pressure setting? I have a Holley blue pump and an Aeromotive regulator. Also, I made the monumental error of removing the  APT piston adjuster, without counting threads. Do you have any ideas on how to adjust it, or do you have a baseline setting?

[Frank400]

If you cup the top of the air horn and the situation improves, that tells it is lean and wants some more fuel.  As for the rest, knowing what engine you have and what's been done to it would help a lot (in fact, it's paramount).

    Knowing what has been done to the carb is very important also, and if it has been rebuilt at some point, what parts are in it (Cliff's parts, auto parts store kit, etc).  It DOES make a huge difference.