Need help with vacuum routing on 84 Suburban! Yikes!

[Corellian Corvette]

I'm trying to get my Sisters '84 Suburban running right. Myriad of little problems going on, but what's really rattling me is the engine vaccum routing.

After some visual checks this weekend I realized that there were a bunch of things going on. She had no Vacuum advance. The EGR was not holding vacuum (but it wasn't getting vaccum anyway). There is some sort of idle compensator that is vacuum powered connected to an electrical switch that is not working.

It appears there are a couple of thermostatic vacuum switches; one on the air cleaner, one on the front of the intake manifold and one on the thermostat housing.

The one on the thermostat housing is clearly broken. It looks like it takes vacuum from the carburator and re-directs it to the Vacuum advance and some other places.

The junction on the manifold - i'm not sure where those go. The vacuum source for that also provides vacuum for the idle compensator.

The one on the air cleaner looks like it opens a valve on the air cleaner and also activates the EGR valve.

To mix it all up it looks like there are some check valves in there to make it even more confusing.

I have no idea if any of these are going to the right place but most of the original hoses are cracked or corroded. I've tried to replace all the ones I could with the exception of the ones going to the thermostat since that is broken. I've actived the vacuum advance straight off a ported carburator outlet so at least that part is working.

So first - is there a place to get a new vacuum switch on the Thermostat housing?

Second - is there a good diagram for where all these hoses go? OR - is there a more simplifed way to activate the EGR, Vacuum Advance, and idle compensator and eliminate all these hoses?

Third - what are the conditions where the idle compensator is activated? I confirmed that the compensator is getting vaccum, and I've confirmed that the switch is getting power. But I'm not sure when/how that is supposed to be actived. Why does the switch have an electrical connection AND a vaccum connection?

Any help here would be greatly appreciated.

[Blazer86]

http://picasaweb.google.com/BarnesEJ/Emissions

I have a few VAC hose diagrams. Maybe one of these is right for you.

[ChevyTech]

Go to this site and page down to aprox Fig 63
http://www.autozone.com/az/cds/en_us...rInfoPages.htm

If you can’t find the correct diagram, go back at pick the correct vehicle information for your sisters suburban and work your way through the menus.

[Blazer86]

The autozone site was great. Thanks
I will take my pic's down now.
Again, Thanks to ChevyTech