focus juddering
Hi please could some one help me i have a focus 1.8 tdci zetec 3 door 2008.when i brought the car it was missing around 2000 revs i had it serviced at fords still the same i changed fuel filter still the same i changed a sensor which i cant remember what its called that cost 85 pounds still the same now when i take the revs past 2500 revs engine malfuction light comes on but the car stops misfiring and drives like it should do as soon as i turn it off and start it back up starts missing until engine malfuction light comes on then i drives fine bit off a head scratcher also black smoke when stretching gears can any one give me advise before i drive it in a wall

 

Black smoke may provide a clue here.
Black smoke coming from a diesel engine can indicate a defective injector, or not always functioning injector. Insufficient air can cause black smoke too , but shouldn't cause a misfire on only one cylinder.
I would suspect one of the injectors is overfueling.

 

thanks mate ill get it checked out