[s-cars] UrS vacuum lines

[David Forgie]

There are four vacuum lines that come off the intake manifolds of our 20VT engines (AAN, 3B,
 ABY and ADU):  http://12v.org/urs/3B_Vacuum_Tree_1.jpg  (ignore the "3B" thing).

1. The first one goes to the fuel pressure regulator and if it has a problem then you  will not have
 4 Bar across the injectors as the ECU expects.
http://forums.quattroworld.com/s4s6/msgs/21108.phtml

2. The second goes to the MAP sensor in the ECU, via the moisture trap. This is the green vacuum line that people tap into for a boost gauge.
http://forums.quattroworld.com/s4s6/msgs/20401.phtml
http://forums.quattroworld.com/s4s6/msgs/20417.phtml

3. The HVAC climate control system, used to open and close valves, flaps, etc. (Sorry no additional
info on this - never had a problem - no incentive to document).

4. The rear diff lock controller for the 92 to 95 model year UrS4 and UrS6s (eliminated in the 95.5
 and 96 and 97 UrS6s in favour of EDL).  This is a purple line.  More diff lock info here:
http://forums.quattroworld.com/s4s6/msgs/170940.phtml

Hope this helps somebody.

Dave F.