The 190E had similiar problems. I did the same in replacing the cap, rotor, wires and plugs.
Additionally through the suggestion of a MNZ tech, I bled the injector lines at the fuel distributor. A lot of gunk came out but the results were impressive. I have also read on this site of others doing the same and seeing a lot of crud come out. You may want to try it.
Just be careful: raw fuel and a running engine.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)