aux air valve opening?

[narfire]

Wondering when cold (30 degF/ -2 ish dC) how big the opening should be in the aux air valve on the FI engines.
Car was running rough at start when cold and am wondering if the opening is not big enough, or not closing. Currently it is about 1/8th inch square or perhaps a tad bigger when I just took it off the car at the above temps.
I'll leave it at room temp here for a while and see if it closes up.


Update... put the valve over the opening of the kettle to see if the hole would close. Nope,still see air and I can suck air easily back through the thing... Guess it is time for another, see what I have at the shop.

[rlux4]

The opening isn't very big, even when very cold. As an experiment I put in a 1/4" gate valve and opened it a little at a time to see how much opening would be optimal. I found anything past 50% (1/8" diameter aperture) would be too much air and stall the car. And it really needs to be closed completely when warm IMO.
On top of that are other components that are affected by cold. I just replaced my AFM because it would cause the car to buck under acceleration until the engine had gotten to above 120°.
Ron

[narfire]

Thanks Ron
I did some snooping and found this on a previous thred
http://www.hiperformancestore.com/Ljetronic.htm
About halfway down the topic on the AAV comes up.

Basicaly the thing gets gummed up over time and can hinder the bimetalic plate from working properly. Clean with carb cleaner,rinse and dry. One can adjust the opening with the little nut. More open, better cold starts, smaller opening and tight closed, better performance as compared with some unmetered air getting by with a larger opening and not closing tightly.
I tested mine over a kettle and when warm adjusted the nut to make sure the opening was closed. Did this to a spare as well.
When I get the engine buttoned up I'll give it a go and see if I can set the idle and the car runs better when cold.(er)