I am at a total loss in diagnosing a stalling problem with my 1988 190E, 2.3. The car starts well and idles well but occassionally stalls while warming up and will occassionally stall when coming to a stop (after engine warmup). To date, we have replaced both the fuel pump and the fuel pump relay. I have also gone through the ignition replacing plugs, spark plug cables, and distributor rotor and cap. But, the problem still persists. I have done a search on this board, and cannot get a match that makes sense. There is a lot of discussion over the OVP relay, but I guess that I do not understand how it would impact my problem. I have not done anything with the fuel pressure regulator or the idle stabilization valve. Since these are relatively expensive items, I hate to play the replacment game unless I can get a better understanding of how each would impact my problem and how to go about troubleshooting these accessories. Hopefully, someone can expand on this item. TIA.