Auxiliary Air Valve - High idle

Today I made an attempt to fix the AAV as I suspected this item to be the culprit of the high idle. I'm still amazed how much information can be found on the web on this car. All very detailed and lot's of crafty people coming up with tutorials and fixes. This makes it so much more easy to do fault finding or doing repairs.

Some resources I checked:

http://digital.graphcompubs.com/article/AAV+Rebuild+Procedure/2044913/0/article.html

http://www.bernardembden.com/xjs/idle/index.htm

http://www.jaguarforums.com/forum/xjs-x27-32/aav-valve-replaced-now-101505/

And the best source for this matter:

http://www.jag-lovers.org/xj-s/book/AAV.html

I was hoping that my piston was only stuck and could be losened up easily but it turned out differently. Here the location of the AAV:

At first I removed the airfilter, started up the engine again and put my thumb in the airhole going to the AAV. Idling went down drastically and engine almost stalled.

 The airfilter itself looked recently OK, no immediate need to get replaced.

 In order to access the AAV properly I moved the bar and the filter completely:

Then I noticed this air nipple which was topped off. Likely part of the vacuum circuit? I need to find out to what is should be connected to? 

With the airbox removed I now easily could remove the airhose connected to the AAV. I then noticed this had another airhose connected to it which was topped off with a screw. Now I know this one needs to be connected to the airvent on the distributor cap
( http://erwinxjs.blogspot.nl/2016/09/distributor-cap-and-rotor-replacement.html )

Unscrewing the AAV was done easily. The 90 degree hose going to the manifold however slightly torn at the edge, so that will require a new one.

 I did soak the AAV with WD40 hoping that would do the trick:

But this didn't work at all. So the only option was to dismantle the AAV, following the guidelines:

http://www.jag-lovers.org/xj-s/book/AAVdisassembly.html

Making a small cut to losen up the inner valve holder. The valve itself was severely stuck. I had to jam it out with a hammer! That explains the failure. Before sanding it I tested the thermostat bulb in boiling water but it seems that one wasn't moving at all.

So I have two failures on this AAV. I'm not going to attempt to patch it up and will buy a complete new unit instead. Perhaps slightly more expensive but I would like to get everything in good working order and don't have to worry about that things will play up again shortly. To be continued.

Good I read the following as there appears to be various AAVs around:

http://www.jag-lovers.org/xj-s/book/AAVdifferences.html