Idle hunting when hot + at altitude

[boon]

Took my STI up Turoa a couple of times over the weekend.

Found that when it was hot (i.e. just driven me and 3 mates up the mountain road) plus at altitude (Turoa carpark is at 1600m) the idle would hunt, sometimes between 1000-1500rpm. Listening to the exhaust and watching the motor I could almost swear it was missing every few seconds.

When I came back at the end of the day, it would idle absolutely fine.

When it's hot at sea level, it idles fine. Likewise cold + sea level idles completely OK.

Any ideas?

[Guest]

I think most cars idle differently at higher altitudes

[Guest]

hot idle issues are often a failing afm

[boon]

 Ichi Ban said:

hot idle issues are often a failing afm

Would make sense. Went to a pod filter recently, an oiled one too if I'm not mistaken.

Might clean the AFM and see if it helps, otherwise it can wait until I go MAFless with a Link.