Flathead won't idle but drives fine at speed

[Dan Heston]

So we are trying to figure out a weird situation.  We have a Carter B&B carb on our 51 Dodge flathead.  The engine is a fresh rebuild and it drove great for weeks after it was put back in.  The carb was rebuilt about a year ago.  After a trip last week, we went to drive it home and it wouldn't idle.  Literally, it dies within a few seconds of letting off the accelerator.  I tried adjusting the idle screw and the air adjustment screw.  Nothing seems to work as it's either too fast of an idle inhibiting shift or too little which allows it to stall.  I took the carb off and cleaned the idle ports again just in case I had some dirt or something lodged.  When we put it back on the intake, we got it to run pretty decent, albeit a little rich, but it idled fine.  Upon taking it out again yesterday, it stalled repeatedly.  Any help would be greatly appreciated.  

[plymouthcranbrook]

Check engine vacuum.  Sounds like a manifold gasket leak

[Plymouthy Adams]

check the passage for the idle circuit...choke, idle and high speed fuel feeds all come off the same supply...the throttle plate position in the venturi dictates the circuit in use...the accelerator pump functions to boost the fuel during transition....if choke can be closed to maintain idle showing it is starving for fuel...and as stated it runs good above idle...then the idle circuit is more than not the culprit.

[Dan Heston]

I found that my throttle body was a bit sticky, maybe not allowing the carburetor to engage the idle port.  We'll see.  We took everything apart and sprayed the throttle shaft with WD40 and now we need to test it again.  I'll advise.