This sounds like a set up issue. Blue smoke would indicate engine wear.
Check your air intake is clean / clear - the elephant trunk tubes can delaminate on the inside preventing air getting through. Also check the butterfly mechanism on the intake is opening immediately the throttle is pressed - if it's delayed then this can cause smoke (Ie diesel is injected but insufficient air = smoke. This aside, it may well just be pump adjustment that's needed.
I think it's too early to be even thinking about discarding your engine.
The air filter is clean with fresh oil. The tube is new and intake is working correctly.
How do I know if the injectors are working correctly....could they have an impact on the colour and Collins of smoke?
Many thanks for your help.
Bob