8973815554 Original Isuzu 4JJ1 High Pressure Oil Pump for Excavator

Part number 8973815554 (also commonly written as 8-97381555-4) is a special part number for the high-pressure common rail fuel pump of Isuzu's original 4JJ1 series diesel engine. The high-pressure fuel pump is the core power source of the engine fuel supply system, responsible for pressurizing the fuel to ultra-high pressure (usually exceeding 1600 bar) and stably delivering it to the common rail, providing a pressure basis for precise injection, directly determining the engine's power output, fuel economy, and emission level. As an original standard component, it is mainly suitable for Hitachi hydraulic excavators equipped with Isuzu 4JJ1 engines, such as Hitachi ZX130-5A, ZX200-5A and other models.

This high-pressure fuel pump is a precision plunger type fuel boosting device, which belongs to the heart of the high-pressure common rail fuel system. Its core function is driven by the engine camshaft or gear, which compresses the fuel from the low-pressure fuel delivery pump to extremely high pressure (usually up to 1600-2000 bar or higher) through the reciprocating motion of multiple internal plungers, and continuously and stably delivers it to the common rail for storage, providing constant and sufficient high-pressure fuel for the electronic fuel injector. The original oil pump ensures extremely high fuel supply pressure stability, precise flow control, and excellent response speed. It works perfectly in conjunction with the ECU calibration of the engine, and is the key to ensuring efficient, smooth, and low emission operation of the 4JJ1 engine.

The maintenance core of this high-pressure fuel pump lies in ensuring the ultimate cleanliness of the fuel, regular professional testing, and standardized operation. Fuel system protection: High quality low sulfur diesel that meets national standards must be used, and fuel filters (including coarse and fine filters) must be replaced strictly according to maintenance intervals (usually every 500 working hours or less). This is the most important measure to prevent early damage to precision components inside the fuel pump due to wear or jamming caused by impurities. During disassembly and installation, it is necessary to strictly maintain a clean working environment and replace all relevant sealing gaskets and O-rings. After installation, it is necessary to exhaust the system and may require coding learning or parameter matching for the new oil pump. Based on usage, it is recommended to consider professional testing or replacement of the oil pump every 8000-10000 operating hours or when there is a significant decrease in performance.