Bosch 0438170031 Fuel Injection Pressure Accumulator

The Bosch 0438170031 is a genuine OEM fuel injection pressure accumulator designed for Bosch K-Jetronic and CIS (Continuous Injection System) mechanical fuel injection systems. This critical component serves two essential functions in maintaining optimal fuel system performance and reliability.

Key Functions:

• Maintains residual fuel pressure in the system after engine shutdown to ensure quick, reliable hot starts and prevent vapor lock conditions
• Dampens fuel pressure pulsations from the electric fuel pump, reducing noise and providing smooth, consistent fuel delivery to the injectors
• Features a spring-loaded diaphragm design that stores pressurized fuel and releases it when needed

This accumulator is positioned between the fuel pump and fuel filter in the fuel supply line, operating at approximately 5 to 5.5 BAR (73-80 PSI) system pressure. When functioning properly, it prevents hard starting conditions and erratic engine operation. Common failure symptoms include fuel pressure loss overnight, extended cranking before starting, and fuel leakage from the accumulator body.

Specifications: Genuine Bosch component with OEM cross-reference number 91111019702. Commonly used on European vehicles including Porsche 911, Mercedes-Benz, Volvo, Audi, and other applications equipped with K-Jetronic or KE-Jetronic fuel injection systems.