Patent ID: 8807116

Claim:
A fuel injection system ( 2 ) for an internal combustion engine, for maintaining consistent emission and fuel consumption characteristics despite injection system component wear, comprising: at least one fuel electroinjector ( 1 ); and an electronic control unit ( 11 ) designed to supply the fuel electroinjector ( 1 ), in a fuel injection phase in an engine cylinder, with at least a first electrical command (S.sub.1) to perform a pilot fuel injection (P), and a second electrical command (S.sub.2) to perform a main fuel injection (M), the first and second electrical commands (S.sub.1, S.sub.2) being separated in time by an electrical dwell time (DT) such that the main fuel injection (M) starts without interruption with respect to the pilot fuel injection (P); wherein the fuel electroinjector ( 1 ) is operated such that the total fuel amount (V) injected during the pilot and main fuel injections (P, M) in a fuel injection phase in an engine cylinder remains relatively constant despite system wear, wherein as the electrical dwell time (DT) between the first and second electrical commands (S.sub.1, S.sub.2) varies, so as to adjust total injected fuel volume in accord with predetermined performance data points, the dwell time varies only within an intermediate electrical dwell time range (Z) defined between a first and a second electrical dwell time range, such that the main fuel injection (M) will continue to start without interruption with respect to the pilot fuel injection (P), but also where the total fuel amount (V) variation is smaller than the variation in the first and second electrical dwell time ranges that lie outside of the intermediate range (Z); and wherein the electrical dwell time (DT) between the first and second electrical commands (S.sub.1, S.sub.2) belongs to the intermediate electrical dwell time range (Z).