Hello,
I am back here to report the final outcome. Looks like the injector have not been refurbished before.
Now the injectors have been sent to be refurbished and, after that it finally works fine. The guy working on injector renewing said they were in very poor condition, with clogged nozzles ..
So if anyone else will experience blue smoke, it may be improper combustion due to clogged injector nozzles or due to an injector leaking.
Thank you all