How do I test the changeover valve (82 240D)
 

I have a 82 Euro 240D. On top of the valve cover is a three way "changeover" valve, which, I think, is leaking. Thankfully, I was able to locate a vacuum diagram that is really close to what I have.

So, here is my question. On this picture, if I apply vacuum (or suck) from 2, while blocking 1 and 3, it does not maintain vacuum. I think it should. The car does not shut off, however, if I disconnect the line at [2] and block it, it shuts right off.

http://www.andresguns.com/images_oth..._way_valve.jpg

[1] and [2] go to a valve on the IP which is called the "vacuum control valve"
[3] goes to transmission

is the changeover valve bad?

found diagram for my 1982 240D euro
 

I think this is the closest diagram that I could find that matches my 240D Euro

http://www.andresguns.com/images_oth...%20diagram.gif

#3 goes to trans, correct? There is always a vacuum supply to the trans until full throttle (just about)

suck on #1, actuate the valve, determine if / when #1 closes

do the same for #2

I think only one of them should close completely under full throttle