rough or erratic idle
 

I have a 1987 MB 190E 2.3L. Car idles about 570-670 rpm, but it is a rough shaky idle. It has new plugs, new ignition cables & distributor cap & rotor. It takes off great from a stop sign & doesn't miss that way or on the hwy. Can anyone possibly help on this problem. I have thought it might be the oxygen senor, but thought I might seek help from someone who may have had this problem in the past. Any help would be appreciated.