hi as you can see l have a 2005 renault scenic
but l have no power after the turboblew and l got another one put on but some thing is wrong as the power not there like before dose any one know why thanks john

Check all the hoses to the turbo, one may not be attached properly, and check for split hoses etc whilst you're there.

This would be a good starting point.

did u have intercooler & pipes cleaned out ?
its poss thats it the egr valve that blocked & covered in oil & soot most lack of performance on renault diesels r caused by that.
hope u changed feed pipes to turbo & oil & filter after turbo changed as it may do it again as this is the normal cause for turbo failure on them engines.you r meant to change intercooler as well renault recommend but u can blast it out .
another thought engine did not run away rev up very high on its own when turbo went ? as this can do damage to engine, its runs away because of the oil being stucked in to engine through the turbo failure this could be problem as well but check e g r valve first