Freelander 1 Grey Smoke

I’ve been battling this same issue in my fl1 2004 td4 failed MOT last oct replaced all sensors, turbo solinoid, boost pipes, fuel rail loom, filters, x4 injectors and finally crank pulley and belts…. Crank pulley actually made more difference less smoke and once up to temp nothing just a very slight haze of smoke at the 2k mark