Gst racer im using an air tank and the pressure will hold 15-20psi for about 20 seconds then drop to zero ... I know the throttle body is sapossed to leak a little air through the head ,valve exc.. but i can hear a hissing noise cooming from there an i cant find it .......Everything else is pretty leak free i took a bunch of stuff off an pressurized them by thereselfs.... I have heard of alot of different things like it should hold boost and leak very slow like as in 5 mins???? is that wrong?? Thanks guys i aprreciate it

Regards Paul