A VNT is a variable vane turbo so I would check the vaccum actuator. What kind of vnt? Is it a gtb1756 gtb2056. Is it even Garrett? Was installed by someone else and programmed for it? Im unsure if Land Rover used a variable geometry turbo. If not I'm unsure of where you go from there. VW was one of the first to utilize the technology so my Jetta is plug and play for different ones. Did you do all the work? Where did you get the kit for it?
Your gonna have to volunteer more info if you expect an answer from Texas where zero diesel Land Rovers were sold. Everything that was done to it is necessary with detail to determine whether you even have a problem. Fueling is key to how everything works so just injectors could be it, or metering.....??????
Thanks for the advice guys. The turbo is a Turbo Technics VNT. It turns out my MAF sensor was not working and this has made a big difference. Also, I have not yet done a decat or EGR removal so will see how the remap goes after doing this... My mechanic did call to say this is the first time he has seen a Landy burn rubber though!!
Yeah the m.a.f would be a cause. Might check when you get ready to re-map about using just the m.a.p. sensor. Might cause issues with changed variables. Don't expect anything to be right until programmings done. I would definitely check the injector scenario...try to match it with your different boost maps. More air requires more fuel. Its dangerous without it. Black smoke is better than none. Did you upgrade the exhaust and downpipe off the turbo?
I don't know anything about the turbo brand you mentioned. I've been looking at Garrett turbos like I said for the V.W. Volkswagen is one of the best vehicles for mods due to the programming software. The enthusiasts call it hacking their car. But I'll be damned...you better understand everything about it before trying to use the program to turn off a pesky door chime or whatever. Not real user friendly but offers complete control. I am no expert at all..
You should check around regular diesel forums and find fixed vane tovnt conversions and double check what they do. Some fueling maps for variable vanes arent far off from twin turbo set ups. That's the first diesel turbo swap question I've seen on this forum for Land Rover. I'd spread these questions around. Your still gonna have to be more specific. Is it a vaccum actuator, electric, brake controlled. What mods were done to the intake exhaust...everything matters.