Date registered: Jun 2012
Vehicle: 1998 E320 base sedan @ 160kmiles
Location: Boca Raton, FL
Mentioned: 79 Post(s)
Quoted: 1190 Post(s)
The way W124 starts is different from your W210. Your car has a tip start, meaning you just have to tip the key to start position, (no need to hold), and the engine computer turns the starter relay on which provides power to the starter solenoid. When cranking, the starter has to provide more than 100 rpm and the ECU will turn the injectors and ignition functions on to get to engine to reach certain rpm (450 to 700 if I remember correctly), if not reached the relay is turned off to prevent damage to the ring within X seconds or so.
If your car consistently starts in the first cold morning try, that means fuel pressure is still good.
Few things to check.
1) Make sure the battery is fully charged. In your earlier post you indicated you replaced the starter, and it appeared that the your battery is marginal. Have you replaced / checked the battery ?
2) Have you put any grease on the starter ring gear in installing the starter ?