Aux air valve

[sean sherry]

Early air valve with brass bulb. After repeated searches on the Net I was not able to find any definitive information, either on repairs or if they could be adjusted. So I bought a second hand one to see before I removed mine from under the manifold ( somewhere ) . People talked about tapping them with a hammer, and or, squeezing the bulb. but no information on what the previous operations achieved. Now I know. Maybe this will help others.

Tapping the end plug in reduces the air flow when cold, controlled by the brass bulb. ie., closes up the gap to the movable piston . Squeezing the brass bulb to reduce the internal capacity starts the movement of the piston earlier in the heat range. Should be around 60% I'm reliably told.
My current valve does nothing till over 80% and then is still slow to close. Probably clogged slightly and needs a bulb squeeze.
For the record I have improved mine a bit by squirting some Subaru cleaner down the vacuum hose to the retard system. Not a cure but at least the engine returns to a stable idle when hot, though still a bit slow getting there.
As someone pointed out these units will never be 100% , need electronics for that.......Sean

 

[abl567]

Sean, there is some useful information in this thread, which is surprising

http://www.topklasse.org/forums/showthread.php?t=3229&highlight=Air+Valve

 

[sean sherry]

yes this is a very comprehensive article. I had read it but still didn't understand what tapping in the end plug achieved. Now I know. I tapped my spare unit in as in our mild climate the high fast idle Factory setting for cold engines is not necessary. My car is a Euro Spec where they have "COLD " Winters .Bumping in D can't be good for the Auto Trans or the fibre drive shaft couplings either.
Like squeezing the Bulb it is a bit hit or miss. Fingers crossed......Sean

 

[sean sherry]

Having now read all the threads and with my own observations I now understand what to expect from this ,as some one put it , rather crude piece of equipment. Still, it is well made and repairable which cannot be said for all the modern stuff. Mostly throw away.....Sean

P.S. with the help of a friend squeezed into the rear child seat I have at long last traced the loud cracking noise, over a sharp bump, that I swore was from the right side Dash area. It was the Hard Top Lock behind my right ear, not locking down hard enough. It has an adjustable screw fitting. Noises travel ,so I'm not surprised by this. Just annoyed that I put up with it for so long !