turbo

hi there everyone, I have a megane 2002, new head gasket timing belt and valve stem oil seals all been fitted, I have also fitted 2 recon injectors because I have check injection fault showing, car starts after about 3 presses of the start button, but when I rev it, it is smokey, I have been checking up on here and other sites, some are saying that the turbo could be at fault, is there anyway that I can check to see if it is the turbo or not, thanks