Hunting and racing idle on 1.6 Zetec

[Simon]

My mates P reg escort has a 1.6 Zetec engine in. The idle hunts erratically at times and also it revs very high. It then drops back to normal. Not exactly nice to drive in traffic.

Im thinking maybe the IACV is dirty/clogged? I have checked for air leaks but cant find any.

Any other suggestions?

Cheers