I own a 1.8 16 valve sport. I had probs with revs staying on when backing off throttle and high revving when starting engine started. Ive cleaned the throttle housing and the idle valve which has cured the revs when backing off the throttle but i still have probs with the high revving when starting the engine. Oh its a mk3 by the way fitted with a closed cone type filter which has been on a while now with no probs.
Any info would be appreciated