Well I still got the problem. The problem is that the car idle speed rises when I stop at lights or a road junction. It was rising to about 2000 revs and then dropping back to normal over about 3 seconds. Someone suggested that the problem was the idle air control valve. I removed this valve and found that the mating surface was badly pitted. All the pitting was on the valve face, and the mating surface on the manifold was okay as was the double o-ring. I decided to fit a new valve which was £50 by the way! Result, no change. In fact if anything the problem has got worse which I can't understand. Whenever I stop at lights or a junction now the revs go up to 3000, hold at this for a second then drop down to about 1600 revs over a couple of seconds, they then seem to stop briefly before dropping back to normal over a couple of seconds. There is an adjustment screw with an allen head in the end of the valve but I don't want to start mucking about with it in case I make it even worse. Anybody else got any idea what could be doing this?
Alex