further diagnosis
i really doubt it was the bung, because it was located on the intake track in a low pressure zone that's not affected by positive pressure when on boost. i think it may have had something to do with your actuator (or maybe your BoV). was the exit nipple on the stock actuator bunged or plumbed to another area..?
also, you mentioned that your BoV is fooked..? what is happening to it..? exactly..?