car just shuts off

[Liv2roc]

I have a 84 gt 5.0 carb with duraspark distribitor. problem is I start it up and sometimes it dies and when I try to restart it , it starts and cut straight back off over and over again like 30 times then it will start and run fine. its getting gas I think I can see the acceleratator pump shoot gas in carb. It just like starting the car and turning the key right back off.
could this be the key or ignition switch going bad

 

[885.0conv]

Carbs are not my forte but with my 69 mustang it was finky about the start and idle mixtures sometimes I had to adjust it two to three times a day to keep it running. Carb place said it was fine but who knows the car is gone . Could be an air leak somewhere causing the mixture to be off.