Quote Originally Posted by LysanderSpooner View Post
The vacuum hose that feeds the SAS is bright blue, quite pliable, and refuses to pull off by hand. Because it looks and feels like brand new, and because the SAS passes the test E39 Newbie mentioned in #6 above, I have quite a bit of confidence in it.

As for the ones under or behind the intake manifold, no I have not inspected them. I suppose I should. What are their functions, and what symptoms would their failure show?
Do you mean the hose that connects the valve? Mine was replaced by the PO's mechanic and he used that bright blue "vinyl" tube instead of the old "rubber" stuff. That hose goes alongside the motor to a valve on the back of the intake, strategically placed underneath so it's a b*tch to get to. The other nipple of that valve goes to a vacuum source near the brake booster hose, I forget exactly where. When the engine is cold, the electronic "valve" at the back of the intake opens and allows vacuum to be applied to the SAS valve. The purpose of putting a vacuum gauge on the SAS valve end of that hose is to determine if you have any leaks in the hose and/or if that electronic valve is working. Failure of one or both would result in the valve not opening, or only opening part way, when the engine is cold, thus not allowing enough air from the pump into the exhaust.