When i start up my car when cold it missfires for about 15 seconds and then clears it seems like its running to rich when cold but once the engine is started the revs drop to low around 400 - 500 rpm so would any one know whats going on.
As for that Air aux air valve one way of testing it is to disconnect the black plastic pipe that runs from the valve and go into the throttle housing, then you should see a little hole take a small screw driver and stick it in to the hole, you should be able to feel like theres something hard inside thats the valve. Put the pipe back on then start the engine ,run it for a few mins and then repeat what ive just said this time when you put the screw driver in the hole it should just go threw and come out the other end of the valve then you know its working .So when the engine is cold the valve is closed and when warm its open