I've got vacuum problems with my 2.8 & have replaced all the hoses & connectors I can find. I've located the hoses that go to:
-thermal switch in the air cleaner shroud
-air injector (smog) pump
-cruise control actuator

I've still got a really unstable idle. I know a hose goes to the HVAC system - I found the vacuum switch on the drivers side of the ventilation unit. There's no vacuum present there. I traced the vac line up behind the dash, all the way over to some sort of switch which I can't see. I couldn't find where the vacuum line feeds through the firewall. Anybody know where that's at?