My car starts but won't stay running even when i press on the accelerator. please help?!?!?

okay, so i have a 1965 mustang coupe with a straight six engine(200 cubic inches) and it uses a one barrel holley carburetor. the problem is that the car starts, but wont continue running. i've replaced the fuel pump and its filter, but it still wont idle. also, when i press on the accelerator, the car cuts out almost immediately. i have no idea what's wrong. does any one have any suggestions for me?