FAA Commercial Pilot Airplane (CAX)Aircraft SystemsMedium
In a continuous-flow fuel injection system, which component receives metered fuel from the fuel control unit and evenly distributes it to the individual injector lines for each cylinder?
- AVapor separator
- BFuel injector nozzle
- CFuel manifold valve (fuel distributor/'spider')
- DThrottle body
Show answer & explanationAnswer & explanation
Correct answer: C. Fuel manifold valve (fuel distributor/'spider')
The fuel manifold valve, often called the 'spider' due to its multiple outlet lines, receives the metered fuel flow from the fuel control unit and divides it equally among the lines leading to each cylinder's injector nozzle. The throttle body meters air and signals fuel control, and the injector nozzle at each cylinder simply sprays the fuel into the intake port.
Why the other options are wrong
- A. A vapor separator (if present) removes vapor bubbles, not distributes fuel to cylinders.
- B. The injector nozzle is the final point that sprays fuel into the intake, downstream of the manifold valve.
- D. The throttle body meters airflow and provides input to the fuel control unit, not fuel distribution.
Fuel Manifold Valve (Spider)
A component in continuous-flow fuel injection that receives metered fuel and splits it evenly to injector lines for each cylinder.
- Located centrally, resembling a spider with multiple lines
- Also contains a valve that stops fuel flow at idle cutoff
- Ensures even fuel distribution across cylinders
Memory trick: Spider splits the fuel to every leg (cylinder).