ford focus tdi 1550 - feels like missfire on a tdi - david56

i have a focus and it feels like there is water in the fuel . as i drive it it suddenly has no power and then it will pick up with a sudden lurch and black smoke blows out when you crews it feels like it is missfireing it has had a new egr and top end as the cam belt broke that was 9 months ago. does any one know whats wrong . david56

ford focus tdi 1550 - feels like missfire on a tdi - Peter.N.

Has the fuel filter been changed lately?

ford focus tdi 1550 - feels like missfire on a tdi - david56

do not know if they changed it when they did the work on the top end