4000 Vacuum problems

[4KQuattro]

Hi, newb here.
My 4000 Quattro has been sitting for a few years, and I just started working on it. I got a fuel pump in but it seems like it's still not getting any fuel to the engine.
I found this part in the trunk.


Seems like some type of vacuum pump, which is why I'm thinking that there's no vacuum to get the fuel to the engine. Does anyone know where it goes, or where I can get a new one? I've been searching for anything related to it and came up with nothing.
Also, is there anything specific I should check for vacuum leaks?
Any expert opinions would be greatly appreciated. Thanks

[4kqS4girl]

There's not a lot of technical stuff for the 4kq (or other older models for that matter) on this forum. I would suggest posting over on the 4k forum on Audiworld. Go here: http://forums.audiworld.com/4000/ I'm not trying to take posts away from AZ...just trying to help you out to get your baby running again. I don't, however, think that part is related to fuel though.

[Rocket SLC]

That is a vacuum actuator to lock and unlock either the center or rear diff. It is broken as well, as it should have two ports on top, yours has one broken off. Check to see if your differentials will lock and unlock.
As for your fuel issues, check to see if the cold start valve is working. This is the extra injector on the drivers side of the intake manifold.