Frequency valve answer....

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <199709011819.OAA27955@pear.epix.net> waves@epix.net writes:

> I'm not sure you have a frequency valve on your Audi. VW did away with the
> frequency valve in late 1985 on most cars. I think Audi did it a year
> earlier. This was the switch between CIS w/lambda control and CIS-e. CIS-e
> replaced the freq. valve with a device called a 'differential pressure
> regulator'.

True for NA cars, perhaps.  There are no emission control features on the MB 
engine - it's a modified form of CIS-III.  I believe the closest NA equivalent 
is the MAC11-controlled MC engine in the 5000.  And yes, there's a frequency 
valve - part numbers in original post.
 
(BTW - I was chauffeured to Leeds and back today, two hours each way, in Roger 
 Galvin's 200QT.  Who needs anything better?)   

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club