Firm brake pedal to very soft!

[WicKeD_SS]

I know I seen someone have the same issue here or Pro-T and I cant seam to find it now that im having the same thing. When the car is off the pedel is firm and stops just a few inch down. When the car is running it goes almost to the ground. It stops the car but surely this isnt good.

11" boster, new factory MC , 6 piston baer front and rear.

Dose anyone have any help or maybe direct me to the thread that could help me out!

Thanks
-Brian