The engine can suddenly cut out when driving and either go into safe mode or stop altogether. Have changed pressure sensor, pressure regulator and fuel filter with no joy. Sometimes engine won't start from cold. OBD data shows rail pressure down at 1200 psi instead of 4600 psi when engine starts properly. Fuel pump must be working otherwise there would be no rail pressure at all. Any clues. Could this be a sticking injector given this is recycle system on my Kia?