Factory OEM High Quality New Diesel Fuel Injector 0445120328 5273750 Common Rail Injector for Komatsu Isb/Qsb 6.7L

<Product Description>
This heavy-duty, electronically controlled high-pressure common-rail diesel fuel injector assembly (Part ID: 0445120328 / 0 445 120 328; common OE cross-references include 5283275, 4984434, 4940170, etc.) is precision-engineered for the ISF 3.8L / QSF 3.8L / ISDe series of inline-4 and inline-6 ​​diesel engines. It is widely used in medium-to-light trucks, urban logistics vehicles, construction machinery, buses, and industrial generator sets. As a core actuator within the fuel supply system—responsible for controlling diesel atomization quality and pulse injection timing—it precisely meters high-pressure diesel and rapidly disperses it into ultra-fine particles in response to millisecond-level electrical signals, thereby promoting thorough mixing and combustion with the intake air.

Designed and manufactured to standards emphasizing "micro-level precision fit" and "millisecond-level rapid response," the component features a core control valve and needle valve assembly crafted from aerospace-grade, hardened special alloy steel. These parts undergo ultra-high-precision geometric grinding and low-friction polishing, with surfaces finished in a dense, ultra-hard coating that effectively prevents internal scratching and pressure loss caused by fuel impurities. Upon installation, drivers and technicians will notice immediate improvements: crisp, clean cold starts; quiet, vibration-free idling; and responsive, smooth acceleration during steep climbs, frequent stop-and-go driving, or long-distance cruising. Additionally, the unit reduces black smoke emissions, delivering superior fuel efficiency and a smooth, satisfying driving experience.
</Product Description>

<Product Advantages>
Standardized smart manufacturing and rigorous quality control directly from the source factory. **Cost-effective sourcing by eliminating intermediary markups.** By leveraging standardized production bases for end-to-end quality control and removing unnecessary middlemen, we ensure highly consistent injection pressure and flow rates across all cylinders. This approach not only cuts maintenance budgets but also provides reliable, robust power for vehicle and equipment operations.

**Rigorous testing on ultra-high-pressure digital dynamic test benches.** Low-quality replacements often suffer from response lag and pressure-release malfunctions—causing engine misfires and vibration—as well as wasted labor and costs due to repeated installation and adjustment. Every injection assembly undergoes automated testing before leaving the factory; flow rates and sealing integrity are precisely calibrated across various pressure ranges in simulated high-temperature, ultra-high-pressure environments. This ensures "ready-to-install" performance, drastically saving time and costs associated with installation and tuning.

**Large-scale warehousing and rapid shipping response.** Vehicles used for daily commuting and commercial transport are high-utilization assets; fuel system failures can lead to costly downtime and revenue loss. Our warehouse maintains ample stock, with orders packed and shipped within 24–48 hours of confirmation. This significantly reduces logistics wait times, helping fleets and owners quickly resume operations and avoid losses caused by vehicle downtime.

**Special-quenched alloy needle valves with wear-resistant hardened coatings.** In regions where diesel fuel has poor lubricity or high sulfur content—factors that often cause premature wear and valve sticking in precision components—we provide a superior solution. Our core components utilize high-hardness special bearing steel and anti-corrosion surface treatments. These enhancements offer exceptional fatigue and wear resistance, ensuring stable performance even under harsh conditions and prolonged high-load operation, thereby reducing the extra expenses associated with frequent repairs. </Product Advantages>

<Specifications Table>

| Parameter Name | Parameter Value |
| --- | --- |
| Product Name | Electronically Controlled High-Pressure Common Rail Injector for Commercial Vehicles & Construction Machinery |
| Standard OE Part Number | 0445120328 |
| Cross-Reference Numbers | 0 445 120 328 / 5283275 / 4984434 / 4940170 |
| Applicable Engine Platforms | ISF 3.8L / QSF 3.8L / ISDe Diesel Engine Platforms |
| Fuel Supply System | High-Pressure Electronically Controlled Common Rail System |
| Core Needle Valve Material | Aerospace-grade hardened bearing steel / Corrosion-resistant, high-hardness special alloy |
| Surface Treatment | High-density, ultra-wear-resistant hardened coating |
| Nozzle Hole Machining | High-precision EDM (Electrical Discharge Machining) micro-hole processing |
| Maximum Operating Pressure | ≥ 1800 bar |
| Operating Temperature Range | -40°C to +125°C |
| Internal Sealing Components | OEM-grade high-temperature and swell-resistant special fluoroelastomer (FKM O-rings) |
| Net Weight (Per Unit) | Approx. 0.65 kg |
| Factory Testing Standards | 100% automated test bench verification of flow rates and sealing integrity across all operating conditions |
| </Specifications Table> |  |

<Application Scenario>
Urban logistics and light-to-medium commercial vehicle operations: Light and medium-duty trucks frequently travel on urban and intercity routes, dealing with stop-and-go traffic, rapid acceleration, and heavy-load deliveries. When drivers notice sluggish acceleration, a lack of power when climbing hills under load, or abnormally high fuel consumption, the maintenance team installs a full set of these high-precision electronic injectors. Post-installation, fuel injection response is agile and smooth, and acceleration is powerful, ensuring timely completion of delivery operations. Application Scenario (Construction & Heavy Machinery): Small-to-medium excavators and industrial generator sets powered by 3.8L diesel engines operate continuously at construction sites, facing dusty environments and heavy-load conditions. When equipment experiences delayed starting, severe idling vibration, or stalling under load, maintenance personnel can promptly replace the unit with this fuel injector assembly; its precise atomization restores the engine's robust torque, ensuring the steady progress of construction operations.

Q: Can the product be used immediately after installation, or is a correction code required?
A: Each fuel injector is assigned a unique flow correction code (IMA/QR code) during factory testing. We recommend using a diagnostic tool to program this code into the engine control unit (ECU) after installation to ensure optimal fuel efficiency and smooth operation.

Q: What are the stock levels and shipping lead times for bulk orders?
A: We operate our own factory and large-scale warehouses, maintaining substantial, year-round inventory for this model. Standard orders are typically packed and shipped within 24–48 hours, while bulk orders can be quickly scheduled for production.

Q: How are product quality and performance ensured before shipment?
A: All fuel injectors undergo assembly in a Class 100 cleanroom environment and 100% bench testing across all operating conditions. Tests cover critical parameters such as sealing integrity, pilot injection volume, full-load injection volume, and fuel return volume; our rigorous standards guarantee that every unit shipped is a high-quality product.

Q: What is the warranty period, and how is after-sales support handled?
A: We offer a 12-month warranty. Should a performance failure occur due to non-human factors within the warranty period, we provide rapid replacement or technical support to ensure a worry-free experience.