BuzzBomb 7 Report post Posted June 16, 2016 Hello, as I mentioned in an earlier post, I finally got the '83 635 engine running in the '85 528i. The question I have is, this earlier engine uses the early style idle control that is the slide valve and additional air valve that has the brass adjustment plug. What is the process for adjusting this second valve? I assume it has an effect on idle quality and a little bit on idle speed? Share this post Link to post Share on other sites
