Aux. air valve proper operation

[Yugo_Turbo]

I'll be quick,
Engine from is Fiat Uno Turbo i.e. 1.3 1988.
The question is, how to test is cold start valve, also known as aux. air device/valve, working properly?
I supose be measuring ohm resistance on the two pins on valve itself.
Does anyone know which resistance should multimeter show if valve is working properly?
Also, usefull information would be, does this resistance value differ from valve to valve if its being fitted to other engine?

Unfortunetly I have no pictures of the valve, except those which can be found on the internet.

[4v6]

I have just consulted my autodata manual regarding this item for Uno turbo 1985 to 1990 with Bosch LE2 injection.

The aux air valve should have a bosch part number of: 0 290 140 179.
Terminal resistance is quoted as being 40 to 60 ohms at 20 degrees C.

Other tests you can do to determine if its working correctly are:
With the engine cold, squeeze the air hose between the aux air valve and the inlet manifold and the engine speed should drop.

With the engine hot the aux air valve should be fully closed.
Squeezing the air hose as previously should therefore make no difference to engine speed.

You can also visually check the regulator disc by removing the aux air valve and looking through it.
If its cold the disc will be slightly open ( it allows extra air in to raise the idle speed).
Connect 12 volts to the terminals with the valve removed and the disc will slowly shut as the bimetallic insert heats up, i recently tested the old one off my quattro and it was electrically ok but physically it didnt work.

Hope thats useful.

Tony.

[Yugo_Turbo]

Excellent, thats great information.
Thanks a lot, Tony !