funny carb. question.

[66StangGuy]

ok recently i put on a holley 4bbl vac sec. carb. had an old edelbrock that needed a rebuild really bad... anyway only problem is when i turn the car off for a few minues after its warm and try to start it again.. when i turn the key it fires right away like it always does but after idling for about a second it will stop for no reason. if i try to start it again it will do it again. then finally the 3rd time it will continue to run. what could be causeing this. everything else works fine. could this be a vaccume leak or is the choke resetting after a minute and choking the motor. iv tried starting it while pressing the gas pedal or giving it gas while stating but it does the same thing. i havent had time to mess with it yet but i would just like some more ideas to try when i do that way i dont waiste my time. work too damn much...but the money for my car is nice thanks guys.