Here's the diagrams from hmaservice.com, although I wouldn't try to buy the part unless I was sure about the part number. I'd remove the part and look at it, write down the part number. You can try to clean it too. Take it off and spray some carb cleaner in it first, it might do the trick. To test it, try to suck air through it when you get it off. If you can suck air, it's not working.