The cp4 fuel pump serves as a high-pressure component in modern diesel truck engines. In a cp4 engine, it draws fuel from the tank and pressurizes it up to 30,000 psi for common-rail injection. Twin pistons driven by a camshaft generate the pressure needed for precise fuel delivery. This design improves combustion efficiency and power output while meeting emissions standards in heavy-duty applications. Proper maintenance helps prevent failures common in high-mileage diesel trucks.