That valve operates the fast idle. If you pull the vacuum line from the air cleaner side on a warm engine the idle speed will increase. It should be set at 1200-1250 rpm. When the tube is replaced, engine speed should drop to around 800 rpm, or normal idle speed. Transmission should be in neutral, of course.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.