I might be wrong guys, all I know what that it was black smokeand it smelt like exhaust. This sounds odd too, but a saw a few sparks come out with the smoke sometimes. My tuner is saying is valve float and my upper intake is leaking. Since the valves aren't closing its letting the exhaust smoke come up??
I really doubt your going to force exaust smoke back throught the runner of the head,imrc plate, and throught the runners of the intake out that hose with all that air being forced into the motor.
Im lost to man. Idk what is happening. I know when i pressureize the cold side, there is a leak somewhere over on that side. Ive sprayed soapy water to try and find it but i cant pinpoint it. Maybe it has something to do with it?