I really need to do something with my injectors on my 98 E300. A few weeks ago I went to install a set of 314 Bosio nozzles. All of the injectors with the original nozzles popped at 135 but swapping to the Bosio nozzles all consistently popped at 90 bar, way too low. I put the original nozzles back for now. Car clatters loudly when idling and will start smoking after idling for a while. In contrast, I just got done putting motor mounts in the former AZ bob E300 and that car is very quiet at idle and no smoke. It is night and day difference. Anyway, I know I have seen it somewhere before, but what thinkness of shim do I need to raise the pressure from 90 bar to 135 bar, or roughly 40-45 bar? The shims on the 603 style injectors are too wide and I see part numbers in the EPC for shims for the 606 injectors in various thickness. If I can determine what size I need I will order 6 of them. Either that, of just get a set of Bosch or Monarch nozzles and hope they stay at the same pop pressure as the currently nozzles. I still could never figure out why the Bosios popped so much lower will all other parts the same.

Keep in mind that the "rule of thumbs" regarding shims are just that. The OM606 is much more sensative to shim thickness. For example, the OM617 rule of thumb is .05 = 50 PSI. That may be accurate in some instances, but not all. The OM606 may mean .05 = 100 PSI. You will need shims ranging from .025 or .0001" and up. The various shims come stepped in either .10 or .05 increments. Unless you luck out, you will need a lot of shims to get to where you need to get them at 2,000 nominal PSI +/- 50 or 25 ...

Thanks greazzer. I found a post from last year that talks about the size of 606 injectors being 9.8mm OD or .375 inch working. I believe I may have located shims in the proper size at McMaster but not sure which ones (materials) to get? Any pointers?

https://www.mcmaster.com/shims

harder the better. low carbon and/or spring steel material. Remember, if you get the ones which are stepped at .10, you are really stuck with pressures being constant at 100 PSI, +/- so you may have to hope that your 6 current shims are .05, for example .45 or .65. If you need to bump them, you can only go to .55 and .75 respectively or other increments of "10". So, you will have to determine where your 6 shims are in relation to your injectors PSI so you can decipher how to use the .10 stepped shims. If you have new nozzles, it is OK to go to 2,050 for turbo 135 nozzle holders. That is still in spec, but that's the high end.

I think I am starting to get a handle on what all I need to get. I found various thicknesses in the .375" OD size in low carbon steel. They have thickness from .001" all the way up to .25". I think my only concern at this point is the ID on these is .250". Is that too big of a hole in the middle? If not then I will buy an assortment of these to do 606 injectors. Later on I will need to get some shim sets for 61x and 601/602/603 injectors.