black.smoke and strong smell of diesel?

Hi i have reanult master 52 plate i had a lot of trouble with the turbo it melted pistons and 2 injectors brock the cam shaft so i just changed the engine .from a 5 1movarno it,s starts with no problem the runing is okish but i get a lot of black smoke and a strong smell of diesel can any one surjest anything this van cost me a lot of money before i changed the engine so if its not a cheap fix i will just scrap it