based upon your description it sounds like a vacumn leak. Do you have that giant 1964 Ford looking air cleaner on yours like I have on my 1990 300? I swear, if any of you play golf, here is my analogy....Augusta National wants to appear traditional while updating...Mercedes, same thing...they want/need to appear traditional to maintain existing customer base yet upgrade to maintain leadership technically...*****! Anyway, I would take the aircleaner and look all the stuff.....