i had this problem i found it its the idle air control valve (the shiney metal bit above the manifold cover) they can cost new about £100 area but are really simple to fit you just loosen two bolts a disconect the wire. Once replaced the problem should be fixed. If you a bit of a risk taker for a cheap fix go to the scrapyard and ask for 1 they about a tenner it might fix it, it might not unfortunatly myn didnt but you never no.Anyway i hope this helps!!!
craig, September 2009
