VSV works like this....

When the VSV is
not energised the valve moves to the left and port
F is
closed trapping vacuum in the vacuum tank. The actuator port
E is connected
to atmosphere thru the filter. The TVIS is open.
When the VSV is
energised by the ECU the valve moves to the right and ports
Fand
E are connected (vent to atmosphere closed) to allow vacuum from the vacuum
tank/manifold to reach the actuator. The TVIS is closed.
If everything is working properly, when you go to start the engine the TVIS will close
immediately using vacuum from the tank, and stay open using manifold vacuum once
the engine is running. At approximately 4200rpm the ECU will de-energise the VSV
closing off the vacuum source allowing the actuator to open the TVIS plates.
So if you test the VSV off the car without voltage applied, port F will hold vacuum and
port E won't.
Cheers... jondee86