X2, I kinda hope you'll say the master is under the floor.. If it is under the floor then you need residual valves (2 psi) or verify that the valves are in the master cylinder. Without the residual valves keeping the system full of fluid, that "possibly" could explain why you push the pedal once before you have pressure. Some masters have them built in. Call or e-mail Wilwood and get info on yours before you decide a course of action.

After re-reading your original post, with the info provided, I still feel it's the master cylinder. And I'm hedging a bet that the master has the residual valves built in, but you really must verify all this. Brakes are not something to micky mouse with.