HP4 Diesel Fuel Pump 294050-0190 294050-0191 294050-2194 Common Rail Injection

This high-pressure diesel common-rail fuel supply pump assembly (Part ID: 294050-0190 / 2940500190; common OE cross-references include 22100-E0280, 22100-E0281, 22100-E0282, 22100-E0283, 22100-E0284, 22730-1261, etc.) is precision-engineered. Designed for the N04C / N04C-TQ / N04C-TV series 4.0L diesel engine platform, it is widely used in vehicles such as the Coaster minibus, Dyna light truck, and various other medium-to-light-duty trucks and passenger vehicles. As the core component responsible for generating extreme rail pressure and ensuring a stable fuel supply, it efficiently pressurizes low-pressure diesel and delivers it evenly to the high-pressure fuel rail, guaranteeing a continuous and steady fuel supply across all engine operating speeds.

The pump body is constructed from high-strength forged alloy, while the core plunger and regulating valve spool undergo precision quenching and are treated with an ultra-hard, wear-resistant coating to effectively resist erosion from impurities and prevent internal pressure loss. Upon installation, users will notice a significant improvement in power delivery: cold starts are quick and smooth, idling is stable, and pump operating noise is reduced. Whether climbing steep grades under heavy loads or accelerating during high-speed cruising, throttle response is noticeably sharper and more robust, helping to restore factory-standard driving dynamics and excellent fuel efficiency.

Direct-from-factory manufacturing with optimized costs throughout the entire process. We provide a one-stop, high-standard parts supply solution, eliminating issues such as cumbersome procurement procedures, excessive intermediary markups, and inconsistent quality tolerances. Precision manufacturing via standardized assembly lines ensures highly consistent oil supply pressure and flow rates across all cylinders, delivering reliable power output while keeping maintenance budgets under control.

Dynamic pressure testing across all operating conditions and rigorous quality inspections. To address issues such as oil pressure fluctuations, sluggish acceleration, and intermittent warning lights often caused by inconsistent component quality, every high-pressure pump undergoes automated bench testing simulating real-world high-temperature and high-pressure conditions. Precise testing of sealing integrity and fuel return volume across various pressure ranges ensures the unit is ready for immediate installation, significantly reducing the time and cost associated with assembly and adjustment.

Large-scale, consistent inventory and rapid shipping capabilities. To mitigate downtime losses and operational delays caused by fuel system failures in commercial and commuter vehicles, our distribution centers maintain ample stock of key specifications. Orders are quickly processed and shipped within 24–48 hours, effectively shortening wait times and helping fleets and vehicle owners get back on the road quickly.

High-hardness, corrosion-resistant valve components with wear-resistant coatings. Designed to combat premature wear and valve sticking caused by poor diesel lubricity or high sulfur content in certain regions, critical internal wear components are crafted from premium special alloy bearing steel. Enhanced with specialized surface hardening treatments, these parts offer superior fatigue and wear resistance, maintaining stability under harsh conditions and prolonged continuous operation, thereby significantly extending service life.

High-frequency operation scenarios for commercial buses and commuter shuttles: These vehicles transport passengers over long distances daily, demanding exceptional quietness during idling and stable fuel delivery. When vehicles exhibit slow cold starts, noticeable low-speed vibration, or intermittent "low oil pressure" warning lights, maintenance teams can promptly install this high-pressure fuel supply pump to restore power output and operational smoothness, ensuring passenger comfort and schedule punctuality. Light-duty trucks in intercity logistics and distribution: These vehicles frequently travel between intercity trunk routes and urban roads, often facing conditions that require starting under full load and navigating stop-and-go traffic. When drivers notice sluggish acceleration, a lack of power on inclines, or a significant increase in fuel consumption, maintenance technicians replace the unit with this high-pressure pump. After installation, fuel pressure builds up smoothly and rapidly, and throttle response becomes crisp, thereby enhancing daily transport efficiency.

1. Q: Can the fuel pump be installed and used immediately upon receipt? Is recalibration required?
2. A: Pressure and flow rate calibrations across all operating conditions are completed before the product leaves the factory. Provided the fuel lines are clean, the pump can be put into immediate use after being installed by a professional technician using standard torque specifications and having air bled from the fuel system.
3. Q: What are the lead times and stock availability for bulk orders?
4. A: We operate our own production facilities and warehousing centers, maintaining a steady stock of this model year-round. Standard orders are shipped within 24–48 hours of confirmation, while production schedules for bulk orders can be arranged quickly.
5. Q: What quality inspections does the product undergo before leaving the factory?
6. A: All products are assembled in a Class 100 cleanroom environment and undergo 100% dynamic bench testing at high temperatures and ultra-high pressures. We rigorously monitor pressure buildup, fuel return volume, and sealing performance to ensure the product meets quality standards for vehicle installation.
7. Q: What is the warranty period for the product?
8. A: We offer a 12-month warranty on this product. Should any malfunction occur due to non-human factors during the warranty period, we provide rapid after-sales technical support and service to protect your interests.