Kevin,
You mention that the stutter is there when you start the car. Does it happen during both cold and hot starts or just cold starts?
Assuming that the basics on your car is sorted as James has mentioned (correct valve clearances, correct dwell and ignition timing, correct spark plugs and gap, correct air/fuel mixture), we can then look further.
If it happens during a cold start, then it basically means that the fuel injection lines are not holding residual pressure. That means that pressure has to build up in the affected lines for a few seconds before the engine smooths out - hence the stutter.
A simple way to test if the injectors are the culprits, is to have them tested for opening pressure and spray pattern. Most shops that specialize in Bosch diesel injection pumps should be able to do that for you.
A dribbling injector will give you poor performance and not hold pressure in the lines. If the injectors are fine, then you need to consider the check valves in the fuel injection pump itself.
I had a similar problem with my 230SL and solved the problem by replacing all 6 injectors. Two of the original R1 injectors were dribbling badly and only the R2 injectors are available now from Bosch.
Good luck and keep us posted.
