Black cold start with black smoke (4D56)

Hello friends of the Mechanical Forum, I go to you to request your opinion. I have a Pick Up Mitsubishi L200 year 2000 with 4D56 Turbo Diesel engine, and this is my problem:
a few months ago in the engine of my pick up it had a fault similar to that of a gasoline engine that when it has a bad spark plug wire and it goes to earth the spark creates a well -typical flame that you already know as if the engine gave brinquitos or something that you understand me. I left time passed and finally it was because the problem and it was that an escape valve seat got out of its slot in the butt, well I sent it to repair and for reasons of time I leave it where a friend so that it mounted me the butt but this friend did not notice that the valve seats have already repaired that these leftovers of the surface of the same Valves at the heads of the pistons because the pistons are clearly flat in the head and towards a serious noise the valves did not twist because they were ranking when they were closed, well then I better decided to change the cylinder head for a new one and solved the problem to the days I directed me to the capital and suddenly I felt that I lost strength and it was where I began to see the exesive smoke. Revolutionary devoted to a piston broken by half and there entered oil and it made by the action of the oil in the combustion chamber to be revolutionized in that same moment what I did was stop the engine with speed set so that it would not be unbrown because if you left it you already know.
Well then the engine is better disarmed and full, the piston 2 started by two leaving a hole in the center then began to look for the spare parts and did not find new std pistons nowhere Originals and new shirts and by the way I bought the new turbochar The only thing that changed different were the pistons with that slot thinking that with that difference it was little that the volume of the combustion camera to be modified but in reality I do not know if that is what is giving me problems because the compressions do not seem to be few yet being low I think that fault would not be like that ,, aaaa by the way. Well, the incandestent and are good, they are good. The engine every 5000 km makes its oil change and in 2 oil changes that I have made, I do not spend oil, some colleagues tell me that the problem is of original rings that I put with non -original shirts that I put others tell me that it is injection pump and injectors but I tell them that the strange thing is that before I do not make those fault
please help me with their opinion.
Thank you