Mercedes Benz repair: Mercedes 1988 190E cuts off abruptly, mercedes benz 190e, fuel pump relay

Question
My 1988 Mercedes Benz 190E with only 118000 miles cuttoff abruptly in a heavy 5 PM traffic two days ago.  Suspecting the battery may be the cause I bought and replaced the battery and had the alternator tested at auto zone which got a reading of 13.6.  The guy at auto zone said the alternator does not need to be replaced.  I drove the car okay for two days and again today it cuttoff while I was driving home.  It seems to try to start but dies again.  Now that battery and alternator are ruled out, what might be the problem?  I am stumped.  Please advise.

Answer
What do you have
190E 2.3
or
190E 2.6

Location is critical, where are you?
The temperature in Los Angeles, California is not the same as Washington D.C. or Madison, Wisconsin.

Your description is 99.99% heat related.

The ignition shuts down, however you can still crank the engine.
This issue could be fuel or ignition related.
Fuel Pump Relay failing.
Overload Relay failing.
Fuel Pump failing.
Distributor Cap failing.
Distributor Rotor failing.
Ignition Coil failing.
Ignition Wire Set failing.
Reference Sensor failing.