Engine became VERY hard to start, would not remain running. I noted that the electric 'lift pump' was no longer running whilst glowing the engine.
Interestingly, if I filled the fuel-tank with diesel, it would start and run OK.
Apparently, when the fuel-level was above the HPFP, the lift-pump was not needed. (HPFP = HighPressureFuelPump)
In any case, I replaced the electric lift pump and the engine runs better than it has in many years. (no more occasional loss of power as fuel-level drops)
Interestingly, if I filled the fuel-tank with diesel, it would start and run OK.
Apparently, when the fuel-level was above the HPFP, the lift-pump was not needed. (HPFP = HighPressureFuelPump)
In any case, I replaced the electric lift pump and the engine runs better than it has in many years. (no more occasional loss of power as fuel-level drops)