got a on going problem with my 1.8 zetec si,its got a major air leak somewhere ive changed the idle valve controller so i know its not that,and ive checked the maf sensor too thats fine aswell. Whats happening is it justs holds the revs at 2000rpm in the traffic and if you just blip the throttle at standstill too then the revs fluctuate and if your driving along at 30mph (for example) the car just jerks in gear occaisionally,im stumped!