Hi first time on here, my girlfriend has a 2003 plate mini one diesel the engine judders like it's going to stall ie the revs rise and fall when at idle and when driving! I think it has something to do with some type of fuel saving Eco device because it happened when she first got the car about 6 years ago and ex boyfriend unplugged something which made it stop! Unfortunately that put the engine management light on but the car ran fine! This year when the car had it's mot they plugged this Eco thing back in to turn the engine management light off and the problem has come back! Does anyone know what this problem is and what I need to unplug to make to run ok again??