4964172 QSK19 High-Pressure Common Rail Injector – OEM Quality for Cummins Diesel Engines
For operators of Cummins QSK19 engines – whether in mining haul trucks, offshore power generation, railway locomotives, or industrial compressor stations – the fuel injector is the single most critical component for combustion efficiency and power delivery. The 4964172 high-pressure common rail injector is an OEM‑grade replacement engineered specifically for the QSK19 platform, delivering precise fuel metering, advanced spray characteristics, and consistent performance under the most extreme operating conditions. As part of Cummins' heavy‑duty common‑rail fuel system, this injector is essential for maintaining rated power output, optimising fuel economy, and meeting stringent emissions regulations.
Available as a bare injector or as part of a complete set with all required seals and components, the 4964172 is designed to meet or exceed original Cummins specifications, ensuring a direct drop‑in fit with no modifications required. In this comprehensive guide, we examine its advanced engineering, compatible engine models, common failure signs, professional installation best practices, and why Rsolid Engine Parts is the globally trusted supplier for Cummins fuel injection components.
1. Structural Features & Advantages of the 4964172 Injector
The 4964172 is a state‑of‑the‑art high‑pressure common‑rail (HPCR) injector, developed specifically for Cummins' 19‑litre QSK series engines. Its design incorporates several advanced features to meet the demands of continuous, heavy‑duty operation:
High‑pressure common‑rail architecture – The 4964172 is a solenoid‑actuated injector designed for operating pressures up to 1,800 – 2,000 bar (depending on engine calibration). This ultra‑high pressure enables finer atomisation and multiple injection events per cycle, resulting in improved combustion efficiency, lower fuel consumption, and reduced particulate and NOx emissions.
Precision‑engineered multi‑hole nozzle – The injector tip features multiple laser‑drilled orifices (typically 10 – 12 holes) with carefully optimised spray angles to match the QSK19 combustion bowl geometry. This ensures optimal fuel penetration and air‑fuel mixing, minimising soot formation and preventing cylinder wall impingement.
Fast‑response solenoid actuator – The high‑speed solenoid provides rapid opening and closing times (typically under 0.2 ms), enabling flexible injection strategies including:
Pilot injection – Reduces combustion noise and improves cold‑start performance.
Main injection – Delivers the primary fuel charge for maximum power.
Post injection – Aids in DPF regeneration and reduces particulate emissions.
Hardened alloy steel construction – Manufactured from premium, corrosion‑resistant steel with precision‑ground internal components (plunger, barrel, needle valve). This ensures consistent fuel delivery over thousands of hours, even with varying fuel quality and in harsh operating environments.
Integrated internal filtration – A fine‑mesh inlet filter protects the sensitive nozzle and control valve from fuel‑borne debris, significantly extending service life and reducing the risk of injector sticking or premature wear.
Precision‑ground control valve and seat – The internal control valve and seat are lapped to sub‑micron tolerances, ensuring a positive, leak‑free seal at the end of each injection cycle. This maintains consistent injection timing and prevents fuel leakage into the cylinder, which can dilute engine oil and cause severe engine damage.
OEM‑grade calibration – Each injector is factory‑calibrated to deliver the exact fuel quantity vs. energising time (IQ‑ET) curve required for QSK19 engine control modules (ECMs). A unique trim code is provided with each injector for precise ECM programming.
Operational benefits for fleet operators and plant engineers:
Fuel savings of 3‑6% compared to worn or low‑quality injectors, thanks to precise metering and optimised spray patterns.
Reduced exhaust smoke and particulate emissions – Cleaner combustion helps meet Tier 3 / Tier 4 / Stage V emissions standards.
Quieter combustion – Pilot injection reduces the characteristic "diesel knock," improving driver and operator comfort.
Improved cold starting and low‑speed response – Consistent pilot and main injection ensure reliable ignition in cold conditions and smooth power delivery at low RPM.
Extended injector service life – High‑quality materials and precision manufacturing reduce wear on moving parts, delivering up to 8,000 – 12,000 hours of service life.
100% direct drop‑in fit – Identical to the original Cummins injector in all critical dimensions – no adapters or modifications required.
2. Compatible Engine Models & Typical Applications
The 4964172 diesel injector is specifically engineered for the Cummins QSK19 series – a family of 6‑cylinder, inline, 4‑stroke, turbocharged, heavy‑duty diesel engines with a displacement of 19 litres. These engines are widely used in off‑highway, marine, rail, and industrial applications where continuous high‑power output is required.
| Engine Model | Typical Applications |
|---|
| Cummins QSK19 (Tier 2 / Tier 3 / Tier 4) | Mining haul trucks, large excavators, wheel loaders, bulldozers |
| Cummins QSK19 (Marine) | Marine propulsion for workboats, fishing vessels, offshore support vessels |
| Cummins QSK19 (Genset) | Prime and standby power generation for data centres, hospitals, industrial plants |
| Cummins QSK19 (Railway) | Locomotive propulsion, railcar power |
| Cummins QSK19 (Industrial) | Compressor drives, pumping stations, drilling rigs |
Critical cross‑reference: The 4964172 is the genuine Cummins part number for this high‑pressure common‑rail injector. It is commonly associated with the QSK19 platform and may be superseded by later numbers such as 4964173 or 4964174 for certain calibration variants. Always confirm your engine serial number (e.g., QSK19‑****) and existing injector part number before ordering. This injector is typically supplied as a bare unit; sealing washers, O‑rings, and hold‑down components are ordered separately or as part of a complete installation kit.
3. Common Failure Modes & Installation/Replacement Recommendations
Typical Warning Signs That Your Injector Needs Replacement
Rough idle and engine misfire – Inconsistent fuel delivery from a worn, sticking, or electronically faulty injector causes uneven firing, especially noticeable at low RPM.
Excessive black smoke under load – A leaking, sticking, or poorly atomising injector results in incomplete combustion, producing heavy soot and increasing exhaust opacity.
Increased fuel consumption – A worn or incorrectly calibrated injector may over‑fuel or under‑fuel, both of which negatively impact brake‑specific fuel consumption (BSFC).
Hard starting or extended cranking times – Loss of residual injection pressure due to internal leakage or a stuck control valve makes cold starts difficult.
Fuel dilution of engine oil – A leaking injector can allow fuel to run down the cylinder walls and contaminate the sump oil, reducing its lubricating properties and risking bearing and crankshaft damage.
High exhaust gas temperature (EGT) and power loss – Incomplete combustion leads to afterburning in the exhaust manifold, elevating EGTs and reducing available torque.
Engine warning lights / fault codes – The ECM may trigger codes related to injector circuit malfunctions, fuel quantity deviations, or cylinder balance faults.
Professional Installation Best Practices
Injector replacement requires meticulous cleanliness and precision. Follow these essential steps for a reliable, long‑lasting result:
Clean the injector bore and surrounding area – Before removal, thoroughly clean the area around the injector to prevent debris from falling into the combustion chamber. After removing the old injector, use a specialised bore brush and vacuum to clean the injector sleeve and sealing seat in the cylinder head. The sealing seat must be perfectly clean and free of carbon deposits.
Inspect and replace all sealing components – Always install a new copper sealing washer and new O‑rings with the injector. These are single‑use items; reusing them will result in combustion gas leakage and poor heat transfer. Also replace the hold‑down clamp and bolt if specified by Cummins.
Lubricate O‑rings – Lightly coat the new O‑rings with clean engine oil or a specialised assembly lubricant. Never use silicone grease or petroleum jelly – these can cause O‑rings to swell, extrude, or degrade.
Install the injector carefully – Carefully insert the injector into the cylinder head bore, ensuring it seats squarely against the copper sealing washer. Do not force it – if it does not seat easily, check for debris, misalignment, or a damaged sealing seat.
Torque the hold‑down bolt – Tighten the retaining bolt to Cummins' specified torque (typically 70 – 90 N·m – consult your engine manual for the exact value for QSK19). Over‑tightening can distort the injector body and cause needle binding; under‑tightening will cause combustion gas leakage and injector movement.
Reconnect electrical connectors – Ensure all electrical connections are clean, dry, and securely fastened. Check the wiring harness for chafing or damage. Apply dielectric grease to the connector pins if recommended.
Reconnect high‑pressure fuel lines – Replace any high‑pressure line seals or washers (if required). Torque the line fittings to the specified value (typically 40 – 50 N·m). Over‑tightening can damage the line or fitting.
Prime the fuel system – After installation, prime the fuel system to remove any trapped air. Use the hand primer pump or electric lift pump to circulate fuel until no air bubbles are visible in the return line.
Program the injector trim code – Using Cummins INSITE™ service software, enter the new injector's unique trim code into the ECM. This code ensures accurate fuel delivery calibration for that specific injector.
Perform a leak test and cylinder cut‑out test – Start the engine and check for fuel leaks around the injector and high‑pressure lines. Perform a cylinder cut‑out test to verify even fuel delivery across all six cylinders – fuel rate deviations should be within ±3% of each other.
Break‑in and validation – Run the engine through a warm‑up cycle and gradually apply load. Monitor fuel consumption and exhaust smoke levels to confirm correct operation.
4. Why Rsolid Engine Parts Is Your Preferred Global Supplier
Rsolid Engine Parts has been a premier supplier of Cummins, Caterpillar, Mitsubishi, and Yanmar diesel components for over 15 years, serving mining, marine, power generation, and industrial sectors across six continents. Here is why the 4964172 injector from Rsolid is the intelligent choice:
OEM‑equivalent manufacturing – Produced in ISO 9001:2015 and IATF 16949 certified facilities, using identical alloy steel, solenoid designs, and calibration processes as genuine Cummins injectors. Every batch is tested for flow, spray pattern, internal leakage, and electrical response.
100% leak and performance tested – Each injector undergoes stringent bench testing for internal leakage, opening pressure, and fuel delivery at multiple energising times. Calibration test reports are available upon request.
Complete installation kits – We offer the injector together with the required copper sealing washers, O‑rings, and hold‑down hardware in a convenient kit, simplifying your ordering process and ensuring you have everything needed for a reliable installation.
Global inventory and rapid dispatch – Strategically warehoused in Asia, Europe, and North America, ensuring 3‑7 working day delivery to most international ports and airports.
Competitive wholesale pricing – Attractive volume discounts for workshops, fleet operators, and parts distributors. Enquire about our bulk order programme for large mining or marine fleets.
Free expert technical support – Our in‑house diesel engineers provide installation torque guides, INSITE™ programming assistance, and troubleshooting advice via WhatsApp or email.
Solid warranty – 12 months / 2,000 operating hours against manufacturing defects, premature wear, and material failures – with a straightforward return and replacement policy.
Contact Rsolid Engine Parts Today
📧 Email: amy@rinjector.com
📱 WhatsApp: +86 15975376778
Whether you need a single 4964172 injector for a running repair or a full set for a complete Cummins QSK19 overhaul, Amy and her team will provide a detailed quotation, stock confirmation, and shipping schedule within 2 hours. We also supply complementary parts – injector harnesses, fuel filters, seal kits, and complete fuel system components – for comprehensive engine rebuilds.
Choose the 4964172 high‑pressure common‑rail injector from Rsolid – engineered to deliver precise fuel metering, lower emissions, and reliable power for your Cummins QSK19 diesel engine.
