96 Grand Voyager Air Intake Manifold

I am trying to find a good diagram or explanation as to where the hoses connect on the Throttle and air intake manifold of a 96 Grand Voyager.
After taking out the manifold to replace the gasket and to reach the back 3 spark plugs, we have an air hose that we cannot remember its location. The van runs but it shakes because of the incorrect position of this hose or tube.
It is a strange tube that has a rubber bulb in the middle ( like a liquid dropper). I have searched thru the Haynes Repair Manual and cannot find any explanation on the location of this tubing.
I appreciate any suggestions you have. Here is an example of what I can find, but it's not enough detail.

http://autorepair.about.com/library/faqs/bl753f.htm

According to this picture it appears to attach to the Throttle body, but it does not.
Thank you !!

Which engine? What is the other end of the tube attached to? Diameter?

The hose or vacuum tube is about 3/16, very small. It comes off the Manifold and it may possible attach to the VSC, if we can find out what that is and where. We believe it to mean Vehicle Speed control or Vehicle Stability control. We found someone with the same van and their is capped off at the mainifold. But our van is running ruff with it disconnected. We have one vacuum tube going to the throttle and one to the EGR valve, its the third one we are looking for its location.
Thanks again for any help !!

Well, I took the part to the dealers today and they looked it up. It is the Leak Detector pump harness. We found the connection almost under the floor board on the drivers side.
Thanks for your help !