Audi a4 2.0 170 diesel

when cold i struggle to start it and white smoke comes from exhaust, once its running it drives perfect, oils fine doesnt lose coolant or overheat,
very sluggish when it starts sound like its missing and cutts out unless you rev it, but again once i start driving it and its warmed up its fine all day, as doon as i leave it parked a few hours it will struggle to start again.
any help please
thanks
carwyn

 

Carwyn, it would help to have a model year. Also, be patient, not a lot of TDI A4s in the USA.

 

Good Day Every one, I have a 1.8T CDH motor and had some idling issues, I took it to a local mechanic for the idling issues and he replaced the injector O rings, the car idles perfect after I received it back from the mechanic and runs normal, but I noticed after getting the car back from the mechanic there is white smoke after the choke has stopped when starting the car, if I reverse out of my drive way the smoke makes a cloud in the street, but after a minute or two of driving the smoke disappears, but when I start it at work before leaving in the afternoon the smoke is back for a couple of minutes again. Is this linked to anything that the mechanic could have done ? It doesn't smell like burning oil.

Please advice me if I should be worried or not.