Whats this connected to on the WUR.

[walt]

Between the numbers 1 and 2 intake runners on an 82SC is the WUR. At its base is a small diameter hose barb connection pointing directly at the number 2 spark plug cable. Can anyone tell me what this is connected to, if anything? Thanks.

[thabaer]

There are 2 air ports, one on either side of the diaphragm. Some configurations use both to vacuum. I think previous PP WUR threads had a variety of factory drawings posted that showed the variation.

Found a thread w/ some useful pics from paulporsche
WUR questions

[Paulporsche]

Walt,
Check out this comparison:

http://forums.pelicanparts.com/uploads3/WUR981085747240.gif

Also try:

http://www.pelicanparts.com/911/911_Parts/1978-83/1-7-2.JPG

[Gunter]

Paul: Is this schematic:
http://www.pelicanparts.com/911/911...78-83/1-7-2.JPG
more like the '78-'79 version? I don't have the deceleration valve on my '80 and the nipple on my WUR is just open.
Where all SC's equiped with a Dec. Valve from factory?

[Paulporsche]

Gunter:
That schematic is good for 78 and 79. If you have Lambda control (1980 on) then the correct WUR is like the second from the right in the photo, ie the enrichment is handled by the DME, not a vacuum. If, like my car, you have no DME, then the older style WUR will provide the enrichment via the vacuum. If you look @ the two left versions in the photo you will see the difference in which line is vacuum and which is atmosphere. The atmo line can either be left open or connected to the upper nub on the throttle body. I have the second from the left (from an Audi 5000) and it works great. I was concerned that if I used the 80 version w/o the DME I would not get enough enrichment, or have to be set up too rich for non WOT conditions, although I think I read yesterday that Souk has that type on his car and has no problems.

I think all SCs had decel valves, although some earlier ones look like the schematic, while the later ones look like the AAV (see no 39).

Many posters have said they have disconnected/plugged their decel valves w/o problems.

[Gunter]

Pau: Could you identify the WURs shown in your photo? Like which one for what year? Thanks.

[thabaer]

Here's some good info to look at if you haven't seen it before

http://members.rennlist.com/jimwms/CIS/CIShome.html

[Paulporsche]

Gunter,
I am not 100% sure, but I think the WUR on the left is through 77, next 78-9, third 80 and up. The one on the right may be for 80+ turbos and cars that need high altitude enrichment.

If anyone has conflicting info, please feel free to correct.