Weird starting problem

I have a starting problem with my Dart. If I use it everyday it will start up no problem but if I leave it even for a day it is practically impossible to start without a push. It cranks over fine but makes no attempt to fire.

If it is push started it fires up easily - i can push start it by myself on level ground. The battery has plenty of power and the starter connections are all fine - i can crank the car uphill on the starter to get out of a parking space to push start it but it won't fire when cranking!

The car is a '63 with a basically stock 360 with electronic ignition - it has the 4 pin ignition module which gets power from the 12v side of the ballast resistor. When the car is cranked the voltage here drops because the ignition switch is only supplying power through the ign2 terminal and not the ign1 terminal - is this correct and is there somewhere else i could power the module from that would get 12v whilst cranking?

I have also run a wire direct from the battery to the module and it still wouldn't start whilst cranking?

The ballast resistor and plugs are new, the leads are fresh and i've tried different caps and rotors with no success. Once it's been started it runs fine and will restart without problems.

Any suggestions??