The PCV has a spring and check valve inside it, the spring keeps the valve closed when the motor IS NOT running, some PVC will close at WOT, some don't depending on if the motor has vacume at WOT It sounds like yours is operating correctly, vacume is high on stock motors at idle, you put your finger over the PVC end and the spring inside did its job, it closed the valve Their designed to suck the bad fumes out of the crankcase when the motor is running, they do a outstanding job of sucking any water or condensation out of the motor also