After removing the air muffler, my VDI stopped working. Maybe just a coincidence, but I am certain that my 5K kick is gone. Is there any chance it need the backpressure to operate properly? The car is still hell-strong to 6K, but I don't get the punch at 5K and she is all done at 7K.

How do I check the solenoid and the actuator? I can move it by hand, but when I rev the car not under load it never opens. I have been suspicious of my ACV for a long time, so it might be that. Please give me your thoughts and thanks for you time.

 

To see that it opens, I stick a hose on it and blow it open.
To see when it opens, I test with a generic boost/vac guage.
I tee it into the hose at the VDI (or Aux ports), run a long hose inside the car & go for a ride.

 

Thanks, I will do that. I can check my 5th and 6th ports that way too. Anyone else care to enlighten me?