Fuel pressure is definitely where I would start. Had a 96 Blazer that just quit while going down the highway. Drove me crazy till I got a fuel rail gauge and found out pump was about 5psi too low for the injectors to work. New pump and it was back on the road. My 93 300e used to have intermittent pump problems, but turned out it was the OVP, but the fuse was good, just the relay went bad and would sometimes keep the pumps from kicking in.