Is it called a idle air control valve or idle air control motor?
?\My sons 1992 Lexus es 300 is doing the same thing. I've read you can clean them and that helps a lot of the time because they are expensive to replace. I called Lexus today (of course thats the highest place!) and it was going to be over $500. Could someone send me a link or a picture so that I know exactly where its located.