Printable View
I did this wrong first up too!
The valve should 'spring closed' with nothing attached to it. The vacuum line needs to come off the maximum depression area just behind the throttle body. Your gauge should be on the manifold after the SC.
Set up like that my vac/boost gauge needle follows my foot position
Sorry Robbomaz, I have been hibernating for the winter. Too cold to screw with the vx til now. I was re-reading the thread and your comment about the vacuum line stood out. Where is the maximum depression area? Any pictures? Are you talking about number 4 on the diagram?
The Isuzu throttle body itself has some vac ports. The maximum depression is just on the engine side of the butterfly. I found the best result came when using one of those.
Hibernating for the winter? That made me LOL! Here on Oz we stay inside during the height of summer!
Great! thanks Ill try that on the next warm day. I currently have it coming from the manifold that the supercharger sits on. Post supercharger.
Boost gauge and fuel pressure reg feed go there
Bypass goes on a vac port on the TB