310T Engine and Supporting Systems Practice Exam

When a nozzle valve sticks open in an electronic hydraulic injector within a common-rail system, the chance of delivering more fuel than the cylinder can safely use increases. The flow limiter valve is designed to cap the maximum fuel flow to the affected injector channel, so even if the nozzle valve remains open, the amount of fuel that can reach the cylinder is limited. This protects the engine from over-fueling and reduces the risk of damage. The rail pressure sensor only monitors pressure; it doesn’t actively stop fuel flow. The rail pressure regulator valve keeps rail pressure in check overall by returning excess fuel, but it doesn’t limit flow specifically to the malfunctioning injector. An unintended fuel sensor isn’t a mechanism that directly limits injector flow.