Cummins original 4326639 Diesel Repair Kit Fuel Injector Fits QSK19 QSK78 Q60 Q23 Q19 Engines For HSK78G Generator Construction Machinery Cross Ref 4087889 4928345 4087886 original new injector

Operators running severe-duty Cummins QSK power units depend on precise fuel delivery, and the 4326639 fuel injector is built to meet that demand. Positioned as an industrial-grade diesel fuel injection component, this assembly supports diesel fuel metering, high-pressure injection, spray atomization, cylinder balance, return fuel control, and combustion protection across demanding mining, generator, oilfield, and industrial power applications.

Engineered features include heavy-duty construction, precision fuel metering, high-pressure compatibility, fine atomization, heat resistance, and sealing reliability. The 4326639 is compatible with the Cummins HPI-PT full-authority electronic fuel system used on QSK23 G-Drive engines, supporting high-pressure injection up to 29,000 psi. Cross-reference numbers include 4088430, 4921360, 4954801, plus 4326639NX, 4326639PX, and 4326639RX remanufactured equivalents. QSK23 fitment must be confirmed by engine serial number, CPL, old injector number, and the official parts manual.

For reliable service, focus maintenance on clean fuel, timely filter replacement, water separator service, oil monitoring, return flow testing, and ECM diagnostics. During installation, verify the part number, keep the work area clean, replace all required sealing parts, inspect the injector bore, and follow official Cummins torque values. After fitting, prime the fuel system, read ECM data, check for leakage, and test idle, smoke, acceleration, and load response.