Vacuum Advance
Senior User
Joined: Jun 2002
Posts: 330
Likes: 1
From: Chandler,Arizona - USA
If you are running a single hose, use the ported vacuum. But, read below.
You should have a ported vacuum switch(PVS) on the heater hose outlet coming from the water pump(a bright greenish blue thing). The PVS allows switching from ported vacuum to manifold vacuum during prolonged periods of idle. It also has something to do with the operation of the EGR valve and emissions control. You can search this forum for "ported vacuum switch". I had a bunch of similar questions that I posted, as I have to get my truck smog tested in October. In addition to what I explained, you should be able to find some detailed information. Good luck!
You should have a ported vacuum switch(PVS) on the heater hose outlet coming from the water pump(a bright greenish blue thing). The PVS allows switching from ported vacuum to manifold vacuum during prolonged periods of idle. It also has something to do with the operation of the EGR valve and emissions control. You can search this forum for "ported vacuum switch". I had a bunch of similar questions that I posted, as I have to get my truck smog tested in October. In addition to what I explained, you should be able to find some detailed information. Good luck!
