I bought 1993 300d, 5 cyl turbo, with 115k a couple weeks ago. It ran very well but had a leak from the valves on the injector pump. Last night, I changed all the o-rings and crush washers as described in the wiki diy here. After restarting, it is running very rough (chug-chug) and smoking. I am guessing that maybe one of the injectors got clogged during the work on the IP, or is it possible that I did some other damage to the IP or it's timing. From researching similar issues on this site it looks like the smoke is unburned fuel from misfiring. I was thinking about backing off the fuel lines on each injector while its running until I find out which injector/cylinder is having the problem and then inspecting/cleaning the injector and compression test the cylinder. I was also thinking it might be trapped air in the line and not sure if I should just keep running the engine for a while or if this might make something worse. Any ideas?