W123 300 1989 hot start difficult
 

My W124 1989 300 TE 4matic starts immediately when cold, when it gets to operating temp it stumbles and runs poorly , missing on some cylinders and then stops completely with sometimes a backfire and exhaust smoke in the engine compartment, it will then refuse to start until it cools down.
When I try to start it will fire sometimes on some cylinders but strangely the wipers did one sweep without the switch being on when the battery was losing its charge after persisting in turning the starter ! anybody had the ame or know how to cure it ? Thanks

should be 124, have a 123 thats running fine

Might be worn injectors or the fuel pressure regulator....

Also, your car is a W124, not a W123.

Hot stall
 

I had almost exactly that problem. I had to wait for nearly an hour before it would restart.

I replaced the cheap Bremi distributor rotor arm with an MB original and all's been fine ever since.

RayH

Please remove and test the distributor cap, rotor, and ignition cables visually and with and OHM meter (multimeter). Do a search for specs I think it's >800 - <1100 OHMS but make sure before you test them. REPLACE anything out of specs. As stated rotor is suspect.

Also make sure the correct spark plugs are installed while you are at it. And test coolant temp sensor for the heck of it.

Good luck with it, PS you may be able to edit the title if you wish (W124)
Acky