FAA Aviation Mechanic Powerplant (AMP)Fuel, Induction and LubricationMedium
A mechanic is inspecting the fuel manifold valve (flow divider) on a continuous-flow fuel injection system. What is the primary function of the fuel manifold valve?
- ATo distribute fuel evenly to each cylinder's injection nozzle.
- BTo regulate the total fuel flow to the engine based on throttle position.
- CTo increase fuel pressure for atomization at the injector nozzles.
- DTo prevent fuel from flowing back to the fuel tank after engine shutdown.
Show answer & explanationAnswer & explanation
Correct answer: A. To distribute fuel evenly to each cylinder's injection nozzle.
The primary function of the fuel manifold valve (often called a flow divider) in a continuous-flow fuel injection system is to divide the incoming fuel equally among all the injection nozzles, ensuring each cylinder receives a balanced fuel-air mixture.
Why the other options are wrong
- B. Total fuel flow is regulated by the fuel control unit or metering unit, not the manifold valve.
- C. Fuel pressure is provided by the engine-driven fuel pump; the manifold valve is primarily for distribution, not pressure increase.
- D. While some manifold valves may have a check valve function, their primary role is distribution, and separate check valves are often used for anti-siphon.
Fuel Manifold Valve (Flow Divider)
A component in a continuous-flow fuel injection system that ensures equal distribution of fuel from the metering unit to all individual fuel injection nozzles.
- Crucial for smooth engine operation and cylinder balance.
- Often incorporates a positive shutoff feature for engine shutdown.
- Distributes metered fuel, does not meter itself.
Memory trick: Manifold is like a 'fuel dispatcher', sending equal parts to each cylinder.