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Phillio99
12-01-2004, 11:54 PM
OK I have been attempting to find a good vaccum diagram and I have a few questions. Is there a difference between the bypass acuator and bypass valve? I am pretty sure the valve has a vacuum line running to the driver side, but I keep finding threads saying a vacuum line runs to the back of the plenum.
Also, Where does the fuel pressure regulator vacuum line hook up as well as the boost gauge vacuum line? For Boost gauge I am thinking right next to the sensor on the return plenum.
Any help would be great.
THanks,
Phil

Duffy Floyd
12-02-2004, 12:17 AM
OK I have been attempting to find a good vaccum diagram and I have a few questions. Is there a difference between the bypass acuator and bypass valve? I am pretty sure the valve has a vacuum line running to the driver side, but I keep finding threads saying a vacuum line runs to the back of the plenum.
Also, Where does the fuel pressure regulator vacuum line hook up as well as the boost gauge vacuum line? For Boost gauge I am thinking right next to the sensor on the return plenum.
Any help would be great.
THanks,
Phil
The actuator is connected to the valve itself which is inside the inlet adaptor and has the short section of hose connecting it to the inlet plenum itself. When boost pressure is present the valve shuts allowing all boost to be directed into the intake manifold. When you lift the throttle vac exists in the inlet plenum which allows the valve to be opened by the actuator recirculating air back into the inlet plenum preventing the blower from caviating.

BobGPz
12-02-2004, 01:38 AM
...For Boost gauge I am thinking right next to the sensor on the return plenum...
Phil, I am pretty sure the Boost guage line comes out under the ABS Master Cylinder and connects to the return plenum (It goes in right next to the Air Charge Temp Sensor). Hope, what little that is, helps some..

Phillio99
12-02-2004, 08:06 PM
See thats what I thought, its a 90 bend, black hose, Ive found two of those style of vacuum hoses, like you said one for the boost/ (vacuum gauge? I think they are one in the same?) the second 90 bend black hose is longer, come from the driver side and I connected to the bypass valve. Was this correct. On the passenger side i found a larger 90 degree bend black hose and i connected that to the top of the egr, once again please correct me if I am wrong.
I have an 89 any pictures of the driver side vacuum trees would be great, actually any pictures of the vacuum hooks up would be great.
THanks,
Phil

BobGPz
12-02-2004, 09:48 PM
"Mike8675209" has a great vac diagram. Either do a search for it or maybe he'll chime in and display/link to it.
I'll attach one in a minute.. sorry, best I got..
EDIT....I think the first picture has some wrong ones I illustrated, I know the other pictures are correct. ;)

Phillio99
12-02-2004, 10:31 PM
That helps a bunch. THank you. If Mike8675209 has a good diagram it would be much appreciated. Anyone else with a similiar picture to the second one posted in the previous thread would be so awesome.
Thanks again,
Phil

Phillio99
12-02-2004, 10:37 PM
I have been poking around all the vacuum lines for my car and I have come to the conclusion that the previous owner wasn't a fan of vacuum lines. The second picture that was posted earlier looks foriegn to me bacuase my vacuum tree has no lines off of it. Almost every vacuum connection was wrong on my car save for the inlet to outlet connection. He got that one right. No wonder my car won't idle.
Thanks for all the help you guys are life savers. Any additional pictures and or posts would be great.
Phil

BobGPz
12-03-2004, 11:00 AM
Found this....first one is from a 1993 SC....
Also a link that have some pics..
http://www.sccoa.com/forums/showthread.php?t=44586&highlight=Vacuum+routing

Phillio99
12-04-2004, 02:43 AM
I know I now have all the vacuum on the s/c and pcv and egr valves correct, now its time for the driver side vacuum lines. I am desperate. Can anyone explain/show/ me diagrams of those trees I have almost no vacuum lines on them and I can't get my car to idle. vacuum barely crests 5 on my guage no joke, before i didn't even know it would move on idle. Please I just want to drive my car with some boost for the first time.
Phil

BobGPz
12-04-2004, 10:49 AM
I did a bunch of searches and canít find that vac diagram.
Best I got for my 1990 is from a diagram I drew to help me remember these.
Hope they help and I hope they are correct.

A) To driverís Windshield Wiper.
B) To passenger Windshield Wiper.
C) Washer Fluid Reservoir.
D) To 1-way check valve, then over to the 2nd small vac tree under center of cowl.
E) To a short 90degree vac line then to a 1-way valve that has two outlets.
Iíll look at this part later today and editÖ.
F) To the Air-Bypass-Valve (SC Bypass Valve).
I THINK THIS IS RIGHT.
Everybody feel free to correct or add. As if you wouldnít anyways.. :rolleyes:


....edit...my diagram didn't post.. :mad:

Phillio99
12-05-2004, 07:04 PM
Can anyone else verify that the above information correct. And does anyone have any other good pictures of the driver side vacuum lines/tree?
Thanks in advance,
Phil