could be hydro locking. cylinder full of fuel, not firing. Certainly not firing, maybe a bad injector... I would pull that cylinders plugs and turn it over, replace plugs. Make sure you have fire on that cylinder before replacing plugs. Make sure you have the right firing order going on. If it is back firing something is firing out of time. Keep re-checking your work.


I don't know, after reading your description again, you may have a valve problem. I would pull the plugs and see if the engine will turn over. If she spins freely without the plugs and has compression in each cylinder, you might just have an ignition/injector problem. Take it one step at a time. Now if that is fine, start replacing plugs and checking correct firing order. With that many miles, the timing chain might be worn enough to have jumped a few links, but I would think you would have other codes thrown as well, but as Dave mentioned, it is possible. But running rough, smoking, certainly isn't firing on all six that is for sure....