Hi Guys,
My car seems to have developed and idle where it sits at around 1000rpm then slowly climbs to 2000rpm before dropping back down and starting to climb again. Does anyone have any ideas as to what it might be? It has an Emerald fitted if that makes a difference.
Cheers.
I cleaned out what I think is some kind of air control valve just under the throttle bodies and that seemed to sort mine out.
Yep it will probably be the IACV! They get really gummed up with carbon and other yuk coming in. I took mine off and gave it a good clean with brake cleaning fluid and made sure the rotary valve was nice and smooth rotating.
The other thing to check is that none of the air bleed vacuum hoses of the TB’s are cracked or split. That would ruin the idle! I replaced all of mine with 3/4mm stuff from DT’s. 
Thanks guys. Had a feeling it might be the IACV, however it seems to have sorted itself out so looks like no need to worry just yet!