Intermittent engine running issue!

[JC]

Mk3 Mondeo 2.2tdi (2006 edge) - I am getting an intermittent problem with the car which causes the engine to splutter as you introduce the throttle… as if there was an issue with the mixture (to rich/to lean). As soon as the engine picks up a few revs it clears and runs fine as you go up through the gears and increase speed. Ford have already looked at it and diagnosed that it was a Mass Flow Sensor issue, but I have subsequently changed that and I’m still getting the issue. I took it back to Ford and they said it’s still showing a fault with the MFS. If I stop the car, turn the engine off and back on again, it normally clears the problem, but it can come back at any point again as you continue driving. If I disconnect the plug to the MFS, then this also cures the issue, but I obviously get the engine warning light come on. Ford felt that it would now need a deeper electrical investigation which was going to cost hundreds and hundreds of pounds. Has anyone experienced these symptoms before with a Ford Mondeo (or other Ford)?

[BOF]

All I can say is that you should check the wiring. An open or a short circuit will do the same thing as a faulty sensor, so it could be one of those. The other thing that often causes problems is a build up of crud (technical term, that) on the sensor. Did the sensor that came out seem 'cruddy'? Your replacement sensor, was it a new, genuine, one?