Re: Excessive throttle pumping required to start
 

There are two well plugs below the main jets on a Quadrajet that leak. This is a well known problem. Rebuild kits even came with a foam block that you put in to stop the leak. The fix is to remove the throttle plate assy, and you will see the two plugs sticking down. Smear a good epoxy (Like JB Weld) on them, let it dry, and reassemble.
It's that easy.