I've written up a DIY procedure for injection pump timing for the 617 engine at this location:
. . .that is based on a suggested DIY procedure by Jim Mahaffey. Jim is a contributing editor of The Star (the MBCA club magazine) and is a well-known MB expert, particularly on MB clocks and radios.
I've used the IP procedure myself on an '84 300D and it does work well. Note that it does *not* require the use of special tools . . .