kerosene wouldnt cause the smoking , in fact it would make less smoke than with diesel , but to be honest kerosene and white diesel are almost same viscosity nowadays .
however he should have added a lubricant to the kerosene , ie 3 litres veg oil per tank full , in order to keep injector pump lubricated properly .
you cant just run on neat kerosene because it has not got enough lubrication in it to lube the pump properly , hence youd need to add veg oil or 2 stroke oil to it .
i would suspect youre smoking comes from the oil seals in the turbo leaking oil past them .
are you using much engine oil at all, in reality youd only need to top up a good engine once a month and then it might only need a small amount of oil if any .
if you are affected at startup then this could be the turbo oil seals , but could also be the valve stem seals passing oil into the ports and combustion chambers when you switch off engine as well .
the 19J engine is prone to allsorts of problems and especially turbo related and piston related .
they usually blow headgaskets and crack pistons .
you might have an injector pump problem but if its passed the emmissions test then the pump should be ok . i would suggest the turbo area is the problem as that wouldnt show up on a warm engine so much , ie emmissions test .
if you had a bad injector pump or rings or head gasket problem then this would pretty much show up all the time whilst its running , a head gasket blown would probably make you lose youre cooling fluid .
the oil you are seeing is deposited from the turbo either into inlet side or into exhaust pipe after you switch engine off , then when you fire it up again you have to pass the oil thru the engine or burn it off in the exhaust, hence the smoke for a bit .
you will see a puff of smoke out the exhaust when you startup , thats normal and in winter youll get condensation on damp and cold days when starting from cold .
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