looks like an unobtanium situation . . . . . I see a few on Ebay but not sure if there are truly operable units.

 

I am not aware of a replacement. Good used is your best bet - but who knows how good it'll be...

The engine will run fine without it (cap the port on the intake plenum). You'll give up a little fuel economy because the computer won't know to advance the ignition timing under light throttle/low load (e.g. highway cruising).

 

Thanks, I will most likely buy a good replacement and open up old unit to see what I see. I should double check line to ensure it has no punctures, etc. that would affect vacuum. Can anyone verify that VW used these units too (as I have read) and if so, what part number? Thanks!

 

searching an older 2008 Bosch catalogue for that VSD PN (0 261 230 001) there is no cross reference to a VW.

there is one to a Saab number, PN 935 803, but that brings up nothing and I think in any case it is an error, as Saab, like Porsche, Peugeot, Volvo et al would have a knock/detonation sensor, a completely different sensor with just a subtle difference in the PN: 0 261 231 001

 

Still not sure how in my research people keep referring to their ability to buy these from BusDepot, a VW supplier?

 

Here's a sketch from the shop manual. I assume the bellows (#4) is the weak link. A pin hole there does two things. 1) it renders the unit ineffective and B) it makes it whistle or moan when the engine is running.

 

Thanks! Interesting schematic

 

I got lucky and found a used one that looked brand new. Some have opened the unit and soldered/ braised the leaking copper bellows but then that affects its ability to expand. Many just cap it off at the port at the intake plenum. I am glad I sourced mine, I did notice an increase in fuel mileage and smoother low end response.

 

Yep, I am thinking that having a working unit is worth it

 

I found this old thread that did a few cross references.

Interesting Bosch Parts list

Bosch parts look-up Has anyone ever used this or looked into it at all to see if it might be helpful in cross referencing parts? I was particularly interested in the manifold/vacuum pressure sensor on my 1983. The only image I see in the listing appears to be a new unit that I believe was...

www.alfabb.com

I did cross reference the pressure sensor from a Bosch cross list I have

Bosch 0261230001

Alfa 115 44 05 014 00

Alfa 6051 86 950

Fiat 60518695

Lancia 60518695

Saab 935 803

 

check early 260-280z cars, they also ran 'L 'jet on there cars( bosch licensed Datsun to copy the parts )

 

That would be a nice resource! Lots if old Z cars to scavenge from.....

 

......except Z don't show a VSD according to the Datsun L.jet manual I just read through:

I am starting to think the VSD is probably unique to the S3 spider.

My 'theory' is the single ECU used on L.Jet Datsuns/VWs etc (as opposed to alfa's two separate ECUs) has taken over the job of a VSD
On the alfa, the ignition ECU handles the VSD.
SteveW (BB member) went into this quite a lot on several electronics forums, and I seem to recall eventually his electronics friend came up with a solution for him.
But that was it....it never progressed.

here is one thread for instance:
Alfa Romeo Vacuum Sensor Device Replacement
and here another:
Alfa Romeo needs Vacuum Sensor Device

Also, Bosch would probably still be making it (at least in its classic range) if thousands of Datsuns, VWs, BMWs, Porsche, Audi, Saab, Peugeot (in L-jetronic form) used one....but for the few thousand S3 spiders left on the road, it makes no financial sense.

all I can suggest is everytime anyone passes a breakers yard and sees an S3, take the VSD out!...one day there might be a fix and everyone will be crying out for cores

.....sure glad I got an S4

 

That is par for the course. I had read a couple of threads where someone converted vacuum data to a chip to control the VSD function electronically. I think most found it easier to just disable it. I am glad I found an operational one, it did make a difference.

 

easy fix. just get a dizzy off a early 3 type bmw, or 2002 car with points, convert the points to a eclectroic ignition ( cost about 45-85 $$ for the kit) you can get a dizzy at [pick and pull, or local wreckers, or ebay. local independent bmw shop ) and stuff that into the car, the car will run well, the ignition has nothing to do with f.i. did to my car years ago. now you don't have to worry about the VSD anylonger.