No Brakes when engine is running

[ellebal]

My issue is that my brakes are rock solid with the engine off.
When the engine is on, the brakes are just about gone.

Before the obvious answers come up, here is what I have done:
1) All 4 wheels have new pads and discs
2) All 4 calipers have been replaced
3) All Brake lines and hoses have been replaced
4) Master cylinder has been replaced
5) Brake booster has been replaced
6) Entire system has been properly bled

Now, what else can I do?

Like I said, the brakes are super great with the car off but once the engine
is running, the pedal goes right to the floor and have almost no stopping power.

I would really like advice on what to do next as I have already spent almost$2500 on this problem and it is still there.

HELP!!!!

[XelderX]

I bet you put the vacuum line for the brake booster on backwards. There is a check valve in it that is supposed to keep the booster from loosing vacuum. If it's on backwards the booster never gets a vacuum to operate.

[worldhazard]

same thing i was just thinking actually