Accelerator pump's duff by the sound of it.
To fix it, remove the original carb, hold it in your right hand, throw into scrap pile and fit Holley 4412.
Easy conversion and does wonders for your power output and gas mileage. you need to find a new air filter housing, though; I used one from a 70's Chevy.
Everything you need to know on this is on the 6066 site. Some advocate the Powertronix set-up but mine runs just fine on the OEM setup.