I replaced the glowplugs on my 1984 300D about two months ago. In the process of replacing plug 5 I removed the injector line from line-five on the injection pump. The little line just popped out of the pump and a little rod was left in the opening. When I replaced it, I inserted the pump line back over the little rod and tightened everything down. Upon startup I had a small engine mis-fire but nothing major. It went away after that initial startup. It seemed this mis would come back sparatically. The only probelm is that the mis is now not sparatic and it has changed into a lope. Like a cylinder is not firing. What is my problem and how can I fix it? Any help would be greatly appreciated.