I am not sure if this will help or not, but you are aware that there are two other connections on the bottom of the VCV? There is an control part on the firewall and my recollection is that it recieves vac from the main line.
I had a similar problem and it took forever to figure out. You have found the vac diagram sticky.
Also check out this post.
http://www.peachparts.com/shopforum/showthread.php?p=1291383
good luck. Is a pain to get it right, but very nice once you get it working.