Flywheel failed

Hey I have a 00, 3.0 doch turbo isuzu trooper, she was driving perfect up untill my flywheel failed so I left it lying up for about 6 months until I found a very clean second hand flywheel for it but as soon as the mechanic fixed it and gave it back to me I had an issue, what is happening now is when I start it hot or cold its idles fine but as soon as I just clutch it nothing else just clutch it she immediately bellows out white smoke and nearly cuts out but when I let the clutch off it clears if I accelerate it burns clean but if I just clutch and accelerate together it immediately starts missing on injection and bellowing out white smoke again, when I put it in firts gear and accelerate to take off it seems to build up pressure with restricted thrust and then it releases a puff of white smoke and away she goes as normal the same will happen in second gear and the she clears off in 3rd and so on, now if i'm driving around all day and I comee to a town or where i'm driving along in 3rd or 4th gear with light or moderate acceleration she will start to shudder and put out the odd puff of white smoke also,

Now we have looked at the furl lines for corrosion and air intake but this does not seem an issue we have by passed main filter with and inline filter just in case hand pump was taking in air and this did not work either, we also replaced the the valve at bottom front of turbo and this did not work. Today we got a second hand flywheel sensor of an engine which was outside for a while so I am not sure if sensor was good or not but anyways it seem to make it even worse to be hones so I am going to get a brand new one of these tomorrow as this seemed to be the only thing to have any effect on it even though it was a worse effect so I just want to eliminate this but to be honest I dont think this will solve it either but I hope i'm wrong. So please is there anyone out there that has experienced this or even seen it and can actually tell me what really is the problem before I loose my mind thanks Dermot