After crawling around under the car for several hours and not having the necessary testing equipment, I broke down and paid a visit to a new independent mechanic. I stayed with the mechanic while they ran the usual diagnostic tests (checked for spark, fuel...). I explained to him that I replaced the OVP in August and that the plugs and wires are less than a month old. He suspected the fuel pumps but was not convinced. After another 20 minutes of looking around, he got the car to shut down on its own and tested the fuel relay. BINGO! The fuel/MIL relay was the culprit. The car has been running fine since. Although while standing by during all the testing, I could hear the bearing in the water pump, so it looks like I have some work to do in the near future.
If anyone is looking for an independent Benz/BMW mechanic in the Detroit Suburbs, A-1 Automotive in Rochester. Excellent group, clean facility and only $62.00/hr labor. The dealer in town is currently $99.
'86 Alfa Romeo Spider
'84 Harley Davidson FLH"X"
'70 FJ40 Land Cruiser (basket case)