The injector with part numbers 0445120389 (Bosch reference) and 612630090012 (Weichai service reference) is a common-rail fuel injection component used in Weichai WP13 series diesel engines . The WP13 is a 12.54L inline 6-cylinder engine with an electronically controlled high-pressure common-rail combustion system .
1. Installation Location
This injector is installed directly into the cylinder head of the WP13 engine, with each cylinder having its own injector . The installation requires strict adherence to electrical system procedures and approved torque specifications . During replacement, ensure the work area is clean to prevent contamination of the precision internal components.
2. Function
The injector receives high-pressure fuel from the common rail and delivers a finely atomized spray into the combustion chamber at precisely metered quantities . It plays a critical role in cold-start behavior, combustion efficiency, and exhaust aftertreatment performance . In the WP13's electronic common-rail system, the ECU controls each injector's timing and duration to optimize power output (353–390 kW) and fuel consumption . If an injector fails, the ECU may activate a "limp home" mode that limits engine speed to 1500 rpm for safe travel to a repair station .
3. Maintenance and Service
Common injector faults include mechanical issues such as needle valve sticking due to fuel contamination or water corrosion, and wiring faults from harness damage or short circuits . The sensor/actuator unit is not user-serviceable; repairs and bench flow-matching should be performed by qualified service personnel using proper diagnostic tools. Weichai recommends using designated spare parts and having maintenance performed at authorized service stations . When replacing, always confirm the part number (0445120389) and use new seals to prevent fuel leaks.
4. Important Notes
Always verify the injector part number against the original unit before installation. The nozzle cross-reference for this injector is commonly DLLA143P1696 (0433172039) . Use only clean, specified diesel fuel to minimize injector wear and maintain emissions compliance
