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Pull vacuum on the FSV source line - your HVAC controls will get vacuum from here. If you pull vacuum from the flappy valve line, with the cap removed from the top of the intake manifold, you will see the flappy valve open (I marked a line on the shaft to see it rotate).
Pull vacuum on the FSV source line - your HVAC controls will get vacuum from here. If you pull vacuum from the flappy valve line, with the cap removed from the top of the intake manifold, you will see the flappy valve open (I marked a line on the shaft to see it rotate).
ive started delving into the vacuum check today. I’ve got the airbox off the top and bottom and I can see the vacuum lines a little bit more clearly now. However I have noticed that I have a spare line that runs along the firewall that isn’t plugged into anything… It seems to run to the passenger side on the right hand drive vehicle underneath the coolant reservoir. It’s clearly unplugged from something and I’ve attached a picture of it But can somebody enlighten me as to what it is and where it should go please. Cheers. This is on a 1997 5 L S4 RHD
This is where the other end goes, under the coolant bottle into the side of guard. ... and the disconnected end is just above the 4 way vacuum junction ... it’s a little bit brown in the end like it’s got hot or was contaminated with oil at some point. It runs along the firewal to the other side.
ive started delving into the vacuum check today. I’ve got the airbox off the top and bottom and I can see the vacuum lines a little bit more clearly now. However I have noticed that I have a spare line that runs along the firewall that isn’t plugged into anything… It seems to run to the passenger side on the right hand drive vehicle underneath the coolant reservoir. It’s clearly unplugged from something and I’ve attached a picture of it But can somebody enlighten me as to what it is and where it should go please. Cheers. This is on a 1997 5 L S4 RHD
Your pictures are too small: can't see enough detail to comment.
Welcome to the rabbit hole! I'm by no means an expert, but I also have an S3 (85-86 model years) and i've been working on it off and on for 3 years. My proudest achievement was getting my car to pass CA smog. I'm sure more knowledgeable folks will chime in, but here is my first, gut-check response:
To answer your question about cleaning, the answer is "No, there is no way to maneuver around the items you need to do without removing the large plenums. They're a pain, but when the car is sorted, it runs great.
The lines under the master cylinder go to the HVAC system, the cruise control module and (i think) maybe a heat valve. However, if you're engine is missing/dying and judging by the state of the vacuum line in pic above, you're likely gonna need to do an intake refresh, which includes testing/replacing the vacuum lines.
Dwyane's Garage has a great write-up on intake refresh. In fact, all of his write-ups are amazing and he deserves free beer at any and every 928 event he ever attends. http://dwaynesgarage.norcal928.org/
Scott Yoo also documented his intake refresh and his is an 86 model year as well. His documentation was also very meticulous and filled in a number of gaps that dwayne's write-up didn't cover since he had a different model. http://www.scott-yoo.com/other/intake.html
Also, go to liftbars.com. If you're using jack-stands, those lift bars are the safest way to use jack stands. Also, the chip upgrade specifically for S3's on that website work really nice. keep that in mind if you end up replacing the fuel dampeners.
Last, but not least, REPLACE YOUR FUEL LINES! They may look good, but if they haven't been specifically replaced, then just do it and sleep easier. Greg makes a set that is bullet proof. OEMs are a little cheaper, but still pricey. However, you can go to a hose specialist and get them rebuilt for a reasonable price. You can also get kits and do them yourself, but I wasn't brave enough to take that on.
good luck!
G
Good luck!
Hello, this thread has been most helpful in helping me determine that the HVAC vacuum line that runs from the bottom of the 4way juction below the master cylinder and to the HVAC vacuum console under the center console is not connected in my 1985 928S Manual. Can someone tell/show me where this line goes through the firewall and to the HVAC vacuum console?
On my 86.5, the lines run in the firewall at the red arrow. The black line is the main vacuum line to the HVAC system and the white line is for the heater valve.
I'm sure more knowledgeable folks will chime in, but here is my first, gut-check response:
