Cummins original 4087977 Common Rail Fuel Injector HPI Diesel Fuel Injector Replacement for QSX23 QSK23 Engine Sprayer Excavator Truck Mining Excavator Dump Truck Spare Parts original new injector

For fleets maintaining Cummins QSK23-powered equipment, the 4087977 fuel injector assembly is a heavy-duty diesel injection component for industrial service. This page focuses on QSK23, while supplier listings also associate the number with QSX23, QSK23 CM2250 and QSK60 applications. Cummins lists QSK23 as a 23 L inline six-cylinder engine rated at 760–950 hp (567–708 kW), with High Pressure Injection (HPI). Equipment coverage includes mining excavators and trucks, generator sets, oilfield power units, construction machinery, stationary industrial engines, rail or intermodal power units, and marine auxiliary engines.

In QSK23/QSX23 applications, the injector supports diesel fuel metering, high-pressure injection, spray atomization, cylinder balance and combustion control. HPI fuel delivery is electronically managed according to load, engine speed, boost pressure and operating conditions. Cummins states that QSK23 injection can reach 29,000 psi to optimize response, fuel economy and emissions; QSK23 G-Drive engines use the HPI-PT full-authority electronic fuel system. Correct injector selection therefore supports consistent engine operation.

Do not order by 4087977 alone. The strongest directly reported cross number is 4326640. Catalogues also group 4902827, 6560-11-1114 and 6560-11-1414 with this injector, but these are search references, not automatic substitutes. Before shipment, confirm the engine serial number, CPL, ECM version, emission level, fuel system, equipment configuration, old injector number, body marking, nameplate and injector photos. This verification reduces mismatch risk across overlapping QSK and QSX listings.