Terrano 2 feels like its about to Stall

[Luger]

Hi Guys

Terrano 2 04 plate
second post so bear with me. Problem started about 3 months ago when the vehicle was held at a steady speed it was coughing, and also felt like it was missing while idling at traffic lights to the extent where it felt like it was going to Stall. Put your foot down and it was off like a dream, hold it at a steady thirty and it starts missing.
Took it to the local garage and they replaced the fuel pump and some of the diesel lines. Still same problem. took it to a Deisel specialist and diagnosed the needle lift. Replaced it and a lot better. After 2 weeks back to the same situation. First thing on a morning crank it and it blows a shed load of grey smoke out, then fine for the rest of the day. a fair bit of Black smoke out after idling or reversing.
Love the Motor but losing faith, any help is welcome

Cheers Lads
Luger

 

[Kamsin]

If it worked to start with, then take it back under the 12 month garantee and let them do it again.
I had a power stearing pump go down on me, took it to Halfords to get fixed 2 weeks later went again, they refixed it at no cost to me and it was as good as ever, they reported to me that the first pump was faulty.