started her up tonite after work, and she was idling slightly higher than normall, about 1k, it was abit cold so i thought ok. Drive it down the road, Up the gears to 4th now I became aware that I didnt even need any throttle, the car was driving itself at about 1500rpm. Weird... Ive had it before. Keep driving cos I cant pull over anywhere, back off the throttle and it takes about 3secs before the car backs off. Now get to the traffic lights and the things idling like a div.... up to 1500, down to 500, back up, down, up... etc. Sound like a bellend sat there with a loud exhaust reving up