Diesel Injecton timing question

[JDmills]

I have been working on my recently purchased 300TD. Most of the car is comming along nicely, except the motor remains the sore spot. I set the idle up today a bit, so that it sounds like it is running the same speed as the parts car I brought home yesteday. The TD seems to shake at all engine speeds, less at a fast idle or above, but it still has a vibration in it. I think that all the cylinders are firing, and it starts fairly well in the cold. What I am woundering is :can an injector be the cause of the shake? In that if it was sticking or injecting the fuel late, that cylinder would not be a doing its share...? Any thoughts on this as to how I can isolate the cause furter.

Thanks
Jason