I have a 1992 Mercedes 190e 2.6 motor. Car has spark, compresson. Was driving to work with nothing apparently wronge at 45 mph when it felt as if someone turned the key off, coasted for 100 ft then felt as if someone turned the key back on. This happened two times within 8 miles. The third time it happened, it has not started since. Three things were suggested to me ovp which I have ordered. Crank sensor and fuel pump relay. Am I on the right track????? Thanks