Going out on a limb here. It may have to do with the ambient temperature now in the summer and your area.
Edelbrocks (Carter) have small fuel bowls + the gas that has a alcohol content of 10 to 15% evaporation happens quickly.Not sure of the type,age,or even if your car has a mechanical fuel pump,if so there may be a drain back problem with the pump. I live in the desert and have installed booster mini electric pumps to prime my old carburetor cars and truck.Click the switch on for several seconds to fill the bowls then after starting click it off and let the mechanical pump do the work. Just a thought.
