Lads Fiesta 1.25 idles ok when you start it up, but if you rev it up when it drops back to an idle it starts to rev up and drop back. Have changed the idle control valve.

Anyone got any other ideas?

Cheers,

Dave

Have you tried just unplugging the maf sensor near the air filter?

Cheers

Rich

Have you pluged it in to a code reader ?

Thanks for the ideas. No codes, also it's a mk5 maf is inside the air box took a while to find it. Think I may have found the problem a split pipe under the air box, looks like part of the breather system connected next to the idle control valve. seems ok at the moment anyway.

Cheers,

Dave

[Edited on 2/6/10 by need4speed]

Look down the front of the cam cover there is some breather pipes that go around the inlet manifold. They are common to perish and split and will give you this.