Started my car up after work today (started fine) but was quite high on idle (just under 2k revs) but that's always been the case with my car, after about 30 secs of sitting there the idle was bouncing BIG time. I turned the ignition off so it was just letting the turbo timer run and it carried on bouncing but obv the Rev limiter wasn't doing anything as it was "off". Once I started driving it and 2-3 mins later it was back to normal and idleling absolutely fine and hasn't done it since. What do people think this could be. I've got an over feeling problem but I didn't think it would make a diff to the idle? Also I have had an idle control valve pack up on a previous car of mine but used to drop idle when hot or cold. Heeellllpppp x