I don't know why the injectors would be causing smoke on start-up.
If they leak, then the beast will have a dribble of diesel inside the chamber which would produce a *bit* of exhaust smoke.. but you state that the beast uses 1ltr of oil in less than 1000 miles.. which is abnormally high and suggests that the smoke is burnt engine oil, not diesel. Forget the injectors for now.
If it's not the turbo being strange, then it can only be coming from inside the combustion chamber... so that means you have a dead oil ring, or leaking valve guides. Seeing as you have looked after the engine AND the beast only does the impression of a Kuwaiti oil field on startup it's more likely to be a valve stem seal rather than a ring.
You'll need an endoscope to poke into the combustion chambers and look at the valves. The affected chamber will have more oily soot on the piston crown and the valve stem(s) affected will be oily. If you have the rocker cover off, you may see that one of the valve stem seals will be poorly seated or damaged.. but this is a camshaft off job.
If the stem seal(s) are knackered, you'll need to take the cylinder head off to fit new ones.. so then change the cam-belt/tensioner/water pump etc. and ALL the seals at the same time.
Otherwise if the car is old/knackered and you're going to change it next year anyway, you could still continue to run it, using slightly heavier (e.g. 15W40) oil... though longer term this will probably damage your catalyst, pollute the planet and you may get a bigger failure (smoking like an Kuwaiti oil field/cops will notice) at any time.
Ralf S.