View Full Version : SC vacuum routing

05-10-2007, 01:39 AM
I'm finishing up an engine swap, just doing the little important things. On the vacuum lines, I have the pcv valve and line to the main vacuum system running off the S/C inlet plenum, each has their own tube. The bypass actuator gets vacuum from the main system coming off a distribution block. The high-pressure return plenum has two small tubes , one for the fuel pressure regulator and one for the boost gauge. One of the big tubes was capped off, but what bothers me is that a line runs from the other big tube across to a big tube on the inlet plenum. That doesn't seem right, as it would bleed boost back into the unpressurized inlet. I think someone was in there messing around before I got it. My problem is that I can't find a good vacuum diagram for what it should be, and the Ford EVTM is worthless; it only shows three vacuum lines and isn't even close to what a SC should be. Any input on this? Thanks.

05-10-2007, 10:30 AM

What year is your bird. If its a 93+ the return plenum will have a fitting "The biggest one" that has two nipples in one. "they are checked so only go one way". One is for the brakes and the other one for the inlet plennum.
You will also need to hook up a line that goes from the Bypass actuator to the inlet for the SC.

05-11-2007, 04:10 AM
It is a 90. Thanks for the link btw, knowing that that block on the return plenum is a check valve clears everything up.