Funny you say that about the cleaning of the butterfly as ive just done the same but on a zetec engine, was idling at 1200 too when it used to dance around at 750 - 1000 before and throttle kept sticking, i unplug the engine management fuse, turned the ignition on, off, put fuse back in started it up coughed and spluttered for a minute took it round the block and its sat bang on 1000 rpm now