Have a Holley 94 carb on my 54 truck 239 ohv that I rebuilt. Truck starts but the fuel and air mixtures screws are not working. I can run them all the way in, and truck still runs when it should die. I know idle should decrease as they are turned in but it doesn't have any effect. Any thoughts? Have tried removing screw and blowing air in holes but no change.

 

It could mean the idle circuit is being bypassed. Throttle plate not closed? Idle screw not adjusted correctly? Power valve circuit engaged/leaking?

 

Really check for vacuum leaks also. Lines and carb base gaskets, etc.

 

I had the very same issue. When I reassembled the carb I inadvertently placed the float tab on the wrong side of the spring. Other than running a little rich the truck ran fine. I knew that if I couldn't lean it until it stalled there was something wrong. Easy fix.