2011 Fiesta 1.4 Zetec auto.

once or twice now when I pull up at traffic lights whether or not I go into neutral, the idle speed goes to just over the 1000 rev mark instead of just under it. Sometime for a few seconds, sometimes stays like that until I move off again.

I once had a similar problem with a Vauxhall Omega and that turned out to be something called a throttle control valve, I wondered if this could be the issue here, whether Feistas had one, where is it and is it easy to replace? Because on the Vauxhall a garage charged me £267 which I don't have spare right now!

I had a mk1 focus 1.6 that did this and it got worse over time. It was a split in a rubber air hose (about 1.5cm diameter I think -  under the inlet manifold). I think your 1.4 is same type of engine so maybe has same hose in same place.

does you engine have a black plastic inlet manifold on the front of it like in this picture. (the four plastic tube things). between the one on the far left and the one next to it you can see a black rubber hose near the top , that's the bit I mean I think, it was around there somewhere.   I took the hose off and wrapped insulation tape round and it and refitted it and it was fine. Bit of a bodge, but I wanted to fix it there and then and not wait for new part.  And somehow I managed to get that hose off and back on without dismantling anything else (although it was not easy)

Thanks for that info. I'll check it out

Embarrassingly, I have discovered the cause of the fault - a particular pair of shoes I own have a thick and wide sole which catches on the accelerator peddle when my foot is on the brake! 

Cheap repair though :-)