Finished out our road trip on Monday without a single hiccup. 32 hours of runtime on the engine, and 1000 miles on the clock, not bad. . . until the dear wifey takes it up the road with all the kiddo's. Pulls out floored doing 42 mph after a full mile. SES light on. Pulls off, shut down, restart, SES light on, now we have full power again. It had extended start time on first start. Fired up right away on the "pulled off the road" start. Code 370 - optic sensor. I drove it, cleared the code, working great. Lift pump was working yesterday morning when I checked, and has good flow too (from all the diesel I blasted all over the radiator). 370 is not my favorite number since my IP just had it's one year anniversary in my engine on Sunday.

Thoughts?

The optical lost track and you went to limp mode. Pra y it was a one time blip and not an experience that will repeat. Mine will give the optical code if fuel is cloudy or full of air.

Try r&r'ing all the connectors around the Inj Pump, and the main connectors at the rear of the engine.
Or, if a Van - the main engine-to-body harness connectors.