Freelander 2003> td4 hunting/surging/ holding back/ detonation/ heavy black smoke

Hi im new to the site,
I have recently had the pleasure of my first landy being a freelander 03 td4, have had trouble on three occassions where she took a few attempts and sum throttle to start, owned her just short of a month, shes hunting abit and sounds like a detenation sound on throttle with heavy black smoke. Done the bmw pcv, fuel, oil and air filters to no effect. Cleaned out egr and intake manifold as from reading posts on landyzone. I work at vauxhall on the spanners and land rover is across the road from us so iv been speaking with the techs, they said low pressure fuel pump common so I give her a new one still to no effect. Previous owner done the fuel pressure regulator and wiring overlay in 2010 as well as 4 bosch injectors changed 07/2013 13000 mile ago.

No obvious split hoses, and occasionly drives ok, however progressively getting worse.

Hopefully get her checked for DTC's this week (may help lol although eml not present when running/driving)

Whats the chances of injectors going down again and what do you achieve from doing a leak back check?

Any checks for high pressure pump to be carried out?

This is also my first thread and diesel vehicle, I can ask the lads tommorrow at work but wanted to get involved on here so as we can learn from each other as i've seen you already do.

I also run her on ultimate/supreme and have added injector cleaner. ( still fault present)

Dispite her troubles, I'm really impressed with her and will keep goin till shes right.

Cheers

Wolf

Not only on throttle but if I try and maintain speed around 50 and 70 is jerky and quiet a violent noise I can only describe as "tutt tut tutt tuttt" constant if tryin to sit at these speeds, when the land rover techs herd it stationary at around 2,500rpm they described it as detonating?

I put our bluepoint eobd reader on but it couldnt see anything however I know this code reader can only see certain things on specific manufacture vehicles.

I will keep you updated.

Cheers

Big Wolf

Exactly how long you had it? May sound daft but has previous owner put petrol in by mistake and tried to dillute it down or is your fuel contaminated with something else? Have you filled her up? May be worth trying a complete fuel drain.