massive headache small problem please help!!!!!!!!!!!

hiya everyone, i seem to have lost a little part/valve or whatever its called, its the one that is directly in line behind the throttle cable and without it my car will only run when reving like hell, i have tapped it up for now, its obviously some sort of air balance thingy mijig, so i was wondering if anybody could tell me what its actually called and where i can get one from, as its hard to order a part without knowing its name, sorry my description is vague, please please please someone rescue me, the car is an '83plate 1.8gti      
Thank you all, Dave (kainesbwza)

Sounds like the idle screw. They're still available from the VW dealer, last time I was there. The O ring perishes, shrinks then they can rattle loose, either out of adjustment or falling off and becoming lost like yours has done. A new one will come with the new o ring seal and prevent this happening for a while at least.

thank you very much my friend i will get straight on to vw parts dep now, cheers again, i will post my results when done, thank you thank you        

well you'd never guess how the afternoon has gone, i went to the place where i noticed that something was wrong with the car and FOUND it on the side of the road, however i ve put it back in but the car still idles at 2000, so a bit more head scratching for me :dontknow:  :dontknow: , thank you for your help too, nice Dave (kainesbwza)

If its that loose, probably needs a new o ring. That should bring your idle down.