Reader Question: My 1993 Mercedes Benz 190E stalls while driving and will not restart. It may restart the next day.
I would definitely start with the basics. Is there fuel, proper fuel pressure? Is there spark and spark timing? You have to be missing one of them – fuel, spark, and compression or spark timing.
Easiest thing to check is for a spark at the spark plug, if no spark there, test the ignition coil and the distributor for a spark. If you have a spark at the spark plugs, then test for fuel at the engine and the at the fuel pump. You should be able to hear a short whine of the electric fuel pump when you turn the key to the ON position.
I have seen many fuel pumps fail when they get over heated, and I have seen MANY ignition control modules fail when they get overheated. Good thing is, a “no start” condition is usually pretty simple to diagnose….or at least to narrow down to a lack of fuel or lack of spark problem and go from there.
These cars are pretty complicated if you don’t know what you are doing and have the proper tools to test with though…so find a mechanic that is knowledgeable with Mercedes or it will probably cost you more money and time than if you went to the dealer for a proper diagnosis.