1406 problem

ok guys i have a 69 dart 340 ld340 intake mild cam and 1406 carb. electric choke seems to work. starts when cold but if it truns off before warm up wont start back up unless i por some gas in carb. when its all warmed no problems what so ever it starts right up and runs good when i go for a drive. oh and my timing is set at 8 before if that matters any. dont know anything about carbs. please any ideas that can help. thanks