(Fix) Holley Carb won't idle unless i keep giving it gas

Here you will learn the cause of the car wont stay on unless you keep giving it gas problem. The mustang has a 650 double pumper holley carburetor and the only way that the car stays on is if i keep giving it throttle. The moment i stop pumping the pedal it dies. idle screw adjustment doesn't work, and will only start good and dies right after. The adjustment made was to the transfer slot on the bottom end of the carburetor. This adjustment pertains to all holley carbs and the other carbs like edelbrock all have a smiliar idea behind how it all works. If you have any further issues that you would like for me to help you troubleshoot, feel free to drop a comment and i will do my best to answer the questions for you.