Yes, the engine will puff through the intake if you apply the throttle.

So what is the location of this device? On the drivers side there is an injector that is part of that big plastic idle screw assembly and on the passenger side there is another device that also has fuel lines to it...would it be one of these?

I have another 6.9 which I could swap parts before buying a new one, which one should I try?

Thanks

Tox!