check your PCV and any other locations that could be leaking air. You likely have a vacuum leak somewhere or as you state, are not getting enough fuel. Clean your float bowls and then work your way back to the tank making sure all the lines and filters are free of debris. Once you get it running and able to idle on it's own, take some carb cleaner and spray it on the outside of the carbs all around the throttle shafts and other locations on the intake that could possibly be leaking. If it starts to die when you spry around something then that is where your leak is...
Post up a pic of your engine bay, we may be able to spot something out of place if that is the case... I have seen quite a few things that were not right about SU's that someone had unknowingly done...
Good luck!
Richard