I tested a FWD manifold i have in the shed & when i sucked on the valve they closed
When the motor is running it will do the same thing.
When you hit a certain rpm the solenoid will activate the vacumm tank(big round cylinder, i cant think of the name of it) that pushes the butterflies open?
This is how i understand the tvis to work, i was stairing and thinking hard when i put my motor together as to how it works and this is what i have come to.