Right, only started doing this recently. From a cold start my car starts first time, then maybe 45 secs to a minute later the revs drop slightly then shoot away up and idle at 2000rpm! Also my temp gauge has stopped working since this. I changed the cold start valve thinking it was this but its still the same. If i start my car and take it into the town, say Asda or something and turn it off and go in, when i come back out and restart the car it idles a little lower, say 1300 - 1500rpm which is obviously still to high! Any ideas