Idle Hunting When Warm Engine

[z0M813M4N]

I have a Focus 1.6 se 2002 petrol which has 93000 on the clock which i bought in October 2011.The problem i have is when i bought the car after a few weeks i realised the speedo was playing up now and then it was not working but then would work fine, i read on some forums that this was the Vss which i bought and had replaced by a mechanic friend which he had abit of a job doing as the old one was a sod to get out but he did it,and now speedo works perfectly, But now i get a problem when the engines reached normal temperature it revs up and down when stationary,it revs between 500 and 950 at steady pulses,but the funny thing is when i push the clutch down the revving stops.So i changed the clutch position switch which made no difference at all.(waste of money) I have also replaced the tps,new Ford plugs and ford leads new Calcium battery still revving up and down till clutch is pressed.It seems to do this more when there is a power load ,rear demister,headlights or front windscreen demister on.Its driving me nuts thinking what it might be, your help would be appreciated.

[artscot79]

idle control valve to be honest id have changed that first only other things are the vol age regulator then the ecu i say idle control

[STEADS]

On the back of the carb/single point injector unit have a look there are two white blanking plugs on my sons these had come adrift/broke taped them up and it sorted the problem i think they are there for different variants where two vac hoses would go worth a look

[z0M813M4N]

idle control valve to be honest id have changed that first only other things are the vol age regulator then the ecu i say idle control

To be honest Arthur i have changed the idle control valve,i took it off originally to try and clean it but no better so i bought a brand new one with a rubber gasket still no change.And ive also changed Pcv valve and hose.Im thinking it might need a Pcm update at a main dealer,what do you think now?

[artscot79]

hmmmm i would say a vacum leak then these issues are a nightmare to locate as theres so many options any number of hoses could have a small hole to avoid spending more money ide take it to ford mate