You need to be absolutely sure the engine mounts are OK. Those who have experienced the effects of bad mounts on W124s and similar models always stress just how much effect mounts have.

With KE injection you also need to be sure of good injectors. Many argue that new injectors (not that expensive) are well worth the expenditure and effort.

Fortunately I have not had rough idle problems to deal with, but these issues stick in my mind from many posts I have read. If and when I have any such problems they will be areas I will investigate.

__________________
107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.