1979 Ford Bronco engine will not stay running

79 bronco. New fuel pump, rebuilt carb, will start upon cranking then die as if no gas, when you pump it during cranking it goes. Brum brum brum and dies, fuel level in carb is correct. No fuel line collapse, recently cleaned gas tank, new cap and rotor, plugs and wires. Recently died on the road and restarted by itself upon coasting. Engine was rebuilt 46,000 mi ago