Hi everyone. Ive got a problem with my 1966 230sl. Every time I leave the engine ticking over, the engine begins to faulter and eventually stalls. When I try to restart it, the enging smells strongly of petrol and fails to start. It normally restarts after 30 minutes
wait after which time it runs lumpy and it will not clear, it just gets worse. When left untill the next day its starts fine again until its left ticking over at traffic lights or queeing, then its a dash to get home asap if you know what I mean.
Ive had the car in and out of M.B. garage and a veriety of tuning specialists but no luck so far. CAN ENEYBODY HELP PLEASE ? phil

 

It seems you have an idle fuel mixture that is entirely too rich. The simplest thing to check is the throttle linkage. Make sure that when you have your foot off the gas that the control lever on the injection pump has fully returned against its stop.

If that is okay, you might consider checking the start valve which is located on the side of the intake manifold. It has a single wire attached to a solenoid mounted to the valve. Verify that there is no voltage actuating the valve with the engine running. To check the valve for leakage, remove it from the intake and see that no gas leaks with the key switched on and the fuel pump running.

A final check is to examine the thermostat assembly at the top rear of the pump. This has two small coolant hoses connected to it and is attached to the pump with two screws. If you remove the assembly, you will find that it has a small rod that presses against a piston in the pump. As the engine coolant heats-up following a cold start, this rod gradually extends, pushes the piston, and weakens the mixture. It is possible that the piston in your pump is frozen in place, so verify that it moves freely. I don't know if the thermostat assembly is prone to failure, but you may want to verify that the rod extends by immersing the assembly in a boiling pot of water.