i have the same problem its shudders when its on idle. when i hold the gas down at just say 2000 revs for a constant period of time it seems to jump up and down the revs by its self even though im actually not pressing any harder on the gas. im kind of hoping it nothing special, some on mentioned changing the lambda sensor which ive done to no effect.
carl, December 2009
tick over too low turn up trottle a bit till ok when warm ondly