English to Polish Tech/Engineering Automotive / Cars & Trucks

Resonance and hammering in the injector rail can produce pressure waves and pressure drop at some of the injectors under certain circumstances, particularly if the combined injector flow rate is relatively large compared to the flow capacity of the fuel rail. Even if fuel rail pressure remains constant, uncompensated changes in manifold pressure would affect the pressure drop through the injectors, with a significant effect on injected fuel mass. Thus, most modern EMSs are designed with fuel pressure regulators (FPRs) referenced to manifold pressure to increase or decrease fuel pressure in 1:1 correspondence with changes in manifold pressure to maintain a constant pressure drop through the injectors so that injector flow is not degraded. An example would be during turbo boost by injectors spraying against a head of pressure in the intake manifold. Any problem that interferes with accurate reference manifold pressure (such as pressure influenced by pulsing in a single manifold runner) arriving in a timely manner at the regulator housing can cause injected fuel mass to diverge from what was intended.