Long story short: I replaced the lower housing for the fuel distributor. This si a 1989 560 SEL. Now there is a vacuum connection on the back of the lower housing, and I have no idea what connects to it.



I do not have any vaccum lines left. The image with the crack in it is from the part I replaced...

Any help would be deeply appreciated...

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)

hb:

The part pictured appears to be an air guide housing.

1) How is the mixture control unit attached to the air guide? All familiar versions had a series of
bolt bosses around the perimeter. There do not seem to be any on the pictured part.

2) The interior of the air guide is at atmospheric pressure, so any connection to it will be either a vent,
or a source of air for another component (such as the idle air valve).

The proper name of the part is the lower housing of the Fuel distributor. It attaches to the throttle intake and is held place by a flange on the bottom part of the fuel distributor.

What I am concerned about is that there is vacuum. This intake, if not stopped, would create a massive vacuum leak... This is not the original part, but a replacement I put in, and I had to subsequently swap out because of another issue. I do not know at this point if the original had this hole, but I have photos from the engine prior to disassembly and nothing is visible in this region...

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)

hb: perhaps you could provide some pics of the part that is the cause of your concern.

Note the terminology:

# 14 is an air guide housing
# 25 is a mixture controller

Attached Files

07-220.pdf (248.7 KB, 53 views)

It is the air guide housing.. (#14)

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)

Sorry for the silence on my part, was preoccupied with an immidiate Family medical emergency. All OK now...

Still trying to figure out what went into this opening...

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)

And the answer is ...


(drumroll...)

NOTHING connects to this outlet! It is a fake, clogged from the factory.

I decided I was going to check this out more carefully, maybe try to start the car. Then I thought that this would introduce a massive vacuum leak. So i decided to find a golf tee to stick into it to close it up for the start test. The golf tee would not go in, I tried from the other side, this opening is a dummy, perhaps reserved for future use. I checked out the vacuum diagrams, nothing originates out of here. Nor could it, being clogged from the factory...!

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)