Fuel Pressure Pulse Damper

The fuel injection systems supply fuel to each cylinder by opening and closing all injectors simultaneously once every engine revolution. At idle, when fuel demand is low, this opening and closing of the injectors is very abrupt and causes a hydraulic pressure pulse to feed back through the fuel supply system. This noise is more pronounced when ambient temperatures are low. Due to tolerance reasons, the fuel rail is mounted solid to the engine. At this point there is an unavoidable transmission of hydraulic pulsations to the engine block. These pulses feed into the passenger compartment wherever the fuel lines are attached and create an unacceptable ticking or hydraulic hammering noise.

Pressure pulsations in the fuel lines can be reduced by installing pressure dampers. A suitable mounting location is immediately in front of the fuel rail as close to the injectors as possible on the fuel inlet side. The pulse damper is located between the fuel supply line and fuel rail inlet connector.