What is "Control Valve II" 1991 S4
06-06-2012, 02:51 PM
#1
Race Car
Thread Starter
What is "Control Valve II" 1991 S4
In front of the intake is something called "Control Valve II" in my 91 S4.
The vacuum lines are connected. However there is a black (ground?) wire connected to...nothing...
I was looking at Tony's "Under the hood" and it says Flappy Valve Solenoid.
So where SHOULD this connect to?
See a LOT about the Flappy Valve inside the intake (to/from) but could not track down the schematic in WSM or anywhere here.
TIA!
Michael
The vacuum lines are connected. However there is a black (ground?) wire connected to...nothing...
I was looking at Tony's "Under the hood" and it says Flappy Valve Solenoid.
So where SHOULD this connect to?
See a LOT about the Flappy Valve inside the intake (to/from) but could not track down the schematic in WSM or anywhere here.
TIA!
Michael
06-06-2012, 02:57 PM
#2
Archive Gatekeeper
Rennlist Member
Rennlist Member
2000 words:
06-06-2012, 03:00 PM
#3
Race Car
Thread Starter
Okay--follow up bonus question...in the top picture--to the right, there is a box with a black, u-shaped wire connected to a long gray wire?
That is what is missing (the gray wire). Did not look like a vacuum hose!
That is what is missing (the gray wire). Did not look like a vacuum hose!
06-06-2012, 03:19 PM
#4
Rennlist Member
That grey wire..is vacum feed from the...either the 5/7 way at the back of the engine, or the area under the brake booster.
That feeds vacum to the flappy solenoid, the U shaped wire..is the vacum hose connector from that line to the solenoid itself.
Porsche uses a 'hard line' vacum hose for distances, and short u shaped hoses to terminate them onto things.
06-06-2012, 03:31 PM
#6
Race Car
Thread Starter
That grey wire..is vacum feed from the...either the 5/7 way at the back of the engine, or the area under the brake booster.
That feeds vacum to the flappy solenoid, the U shaped wire..is the vacum hose connector from that line to the solenoid itself.
Porsche uses a 'hard line' vacum hose for distances, and short u shaped hoses to terminate them onto things.
That feeds vacum to the flappy solenoid, the U shaped wire..is the vacum hose connector from that line to the solenoid itself.
Porsche uses a 'hard line' vacum hose for distances, and short u shaped hoses to terminate them onto things.
Engine is idling nicely and car is okay from 3000-redline but...
On the to-do list!
Okay--found this thread: https://rennlist.com/forums/928-foru...um-source.html
Looks like it goes to the 4-way by the brake booster...now to see if it even there or not...the 4 way or the hose...
06-06-2012, 03:38 PM
#7
Nordschleife Master
In front of the intake is something called "Control Valve II" in my 91 S4.
The vacuum lines are connected. However there is a black (ground?) wire connected to...nothing...
I was looking at Tony's "Under the hood" and it says Flappy Valve Solenoid.
So where SHOULD this connect to?
See a LOT about the Flappy Valve inside the intake (to/from) but could not track down the schematic in WSM or anywhere here.
TIA!
Michael
The vacuum lines are connected. However there is a black (ground?) wire connected to...nothing...
I was looking at Tony's "Under the hood" and it says Flappy Valve Solenoid.
So where SHOULD this connect to?
See a LOT about the Flappy Valve inside the intake (to/from) but could not track down the schematic in WSM or anywhere here.
TIA!
Michael
Hope it posts OK.
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06-06-2012, 03:56 PM
#8
Race Car
Thread Starter
06-06-2012, 05:10 PM
#10
Nordschleife Master
What ever color the vacuum line is, the line to the bottom port of the solenoid has to be vacuum in, and the side port has to go to the intake flappy connection.
06-06-2012, 09:17 PM
#12
Chronic Tool Dropper
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I see.... An intake refresh in your near fitiure unless you can locate the business end of the line that runs under the manifold to the flappy actuator diaphragm thingy. Black poly hose with elbows for end connectors originally. It -may- be possible to fit a new line without popping the intake if you have radio announcers' hands (wee paws for station identification...) but more likely is a mirror and a prayer and lots of patience. I managed to swap the rear knock sensor with the intake installed, not sure if my hand would rotate up enough to fit that hose connector though.
06-06-2012, 09:32 PM
#13
Race Car
Thread Starter
I see.... An intake refresh in your near fitiure unless you can locate the business end of the line that runs under the manifold to the flappy actuator diaphragm thingy. Black poly hose with elbows for end connectors originally. It -may- be possible to fit a new line without popping the intake if you have radio announcers' hands (wee paws for station identification...) but more likely is a mirror and a prayer and lots of patience. I managed to swap the rear knock sensor with the intake installed, not sure if my hand would rotate up enough to fit that hose connector though.
That's a given! I am going to try to wait until the fall or winter to do the intake...
The flappy hasn't been connected since 2009 on this car (just checked pictures); it still passed smog in California so I'm not too worried, especially considering the prior owner. Idle is pretty stable and it opens right up to redline without issue but I know I'm losing top end torque unless it's been forced to an open position somehow...
I do see the connection under the manifold and I think with long forceps I might be able to place it there---plus I do have radio announcer's hands so...
Last edited by mickster; 06-06-2012 at 09:48 PM.
