any ideas lol the rs is revvin high on idle sometimes 2-2.5k... if i leave it sat still it will go down to about 1500 for a few seconds then randomly go back up to over 2000 then start revvin a bit before goin back down to 1500 again... its efi but i cant find an airleak??

 

have you tried to disconnect the idle speed control valve to rule it out? my fiesta rs used to do that due to the isc valve being faulty, when I disconnected it the revs drop very low but it stopped them going up and down.

hope this helps