Hi, I purchased an 84 300SD turbodiesel a few days ago. the previous owner had converted it to run on grease. I am getting a lot of black smoke when I drive the vehicle... how much of this will go away as I run regular diesel fuel through the engine. Also, the trans seems to shift very hard, doesn't slip at all though, so I hope thats good. Any suggestions. I need this car as a daily driver and purchased it as a necessity, though I must admit I really like it as well. let me know what I can do to limit my liabilities...

thanks.