<https://www.rhocar.org/index.php?/forums/topic/45193-mondeo-engine-fault/>
<http://schema.org/text>
"Hi Everyone, \n  \nI am after some advice on my Mondeo, (Not the kit car, I know, but thought I would put this past you very clever people). \n  \nIf you own a Mondeo, (mk3), Then you are probably familiar with the splitting PCV pipe, just behind the inlet plenum. \n  \nWell, after replacing this on my Mondeo, I seem to have run into a very weird problem and presents itself like this: \n  \nWhen I start the car from cold, the idle is much higher than it used to be (Now about 1400-1500rpm) and drops to 1100 after a short period of warming up. Normal idle when warmed up would be 750rpm. If I leave the engine running or just drive off the revs will never drop to the norm, UNLESS I turn the engine off, wait a few seconds and then start it again. \n  \nHowever, it gets weirder.... \n  \nWhen started from cold (apart from the idle being high) everything seems normal. Until it has warmed up! Then if I am in say 2nd gear (2000 rpm) and accelerate to change up into 3rd, (foot off the accelerator drop the clutch), the revs will now shoot up to 3000rpm and stay there until I engage the clutch again. If I accelerate hard the revs could go as high as 4000rpm!!. \n  \nOnce again If I pull over turn off the engine wait 30 seconds, start her up, she's all back to normal between gear changes. \n  \nAt first I thought air leak but this would be the same regardless of stopping and starting engine. \nEngine Diagnostics show no faults and nor does using the elm327 analyser... \n  \nBut I have now replaced all the following: \nICV \nThrottle Position Sensor  \nEngine Coolant Sender \nManifold Absolute Pressure Sensor/temperature  (all in one) \nO2 Sensors Pre and Post Cat \nPCV Valve \n  \nClutch switches are working and so is EGR. \n  \nSo I am left with the ECU, which seems to have a problem switching out of choke/reading mappings until its briefly reset. \n  \nBut before I go down that route does anyone have any other ideas? (apart from scrapping it   ) \n  \nCheers \n  \nNige \n  \n  \n  \n"
<https://www.rhocar.org/index.php?/forums/topic/45193-mondeo-engine-fault/#comment-369660>