What would cause a Carter AVS fuel bowl to go dry?

[Just 6T9 CHGR]

If the car sits for more than a day, the fuel bowl goes dry (no pump shot when pedal depressed)
Takes a loooong time to get her to fire up (fuel bowls to fill up)
What would cause this? Never had this problem with my Holley 750 

[8WHEELER]

I am having the same problems with the wife's car. Rebuilt the carb, same problem. I just got the new Mancini
Hemi fuel pump ''they just got them back in stock'', the diaphragm in the pump can go bad, and it allows the gas
to go back through the pump the direction we don't won't. Her car got to the point it will not start at all, unless
you dump gas down the carb   

Dan