Holley problem ....help!

Holley 65pcfm double pumper fitted to a ford 302 engine. The engine has run fine with this carb in the past but not now. It starts and dies immediatley. It's almost as if it's running just on what squirted through the accelerator pump and when thats gone it stops. I've checked the float levels in both bowls and they are both ok.
It starts every time, but dies every time. help!!

IT's NOT a carb problem...
I've changed the carb for one that I KNOW works fine and it's still doing it. Standard ignition, the car has run before fine, any ideas?
Thanks

Look at the ballast resistor wiring, thats were your fault is, Frank

Sussed it!

The previous owner had fitted a switch in the engine compartment that cuts out the ingition. With the key in the start position, the engine would fire, but as soon as you release the key to the "run" position, the curcuit was dead. Flicked the switch and it starts and runs fine. phew, big relief !!!
Thanks for the advice.

Simon

ps, nice immobiliser!