My 740 Wagon was running smooth untill it just quit on the open road. No restart. I had the wagon delivered by wrecker to my local mechanic and he promptly found a timing belt problem as the tension pully bearings were frozen and belt slipped. After replacing the belt and pully and reseting the time(hopefully), the engine will not start. The fuel pump runs, cylinders getting gas, coil sparks but weak ,and spark at plugs but seems weak. Could it still be a RPM sensor, with spark or maybe a power stage of which I have yet to find on either fender??Any other suggestions?