Which component supplies fuel for engine start?

Which component supplies fuel for engine start?

• A. Boost pumps
• B. XFLOW pump
• C. SOV
• D. Ejector pump

Answer: (A)

During engine start, fuel must be moved from the tanks to the engine at the right pressure so the engine’s starting process can run reliably. The boost pump is designed to provide that initial, pressurized flow, pushing fuel through the start/priming path and into the engine fuel control unit so the engine can light off and begin to run. It also helps guarantee fuel is available even if the main pump isn’t delivering full pressure yet, acting as a reliable backup during start. The other components have different roles. The XFLOW pump is another type of pump used in the fuel system, but it isn’t the primary source for delivering start fuel in most configurations. The SOV is a shut-off valve that controls fuel flow, not a pump. The ejector pump can aid priming in some layouts, but the standard start fuel supply is provided by the boost pump.

During engine start, fuel must be moved from the tanks to the engine at the right pressure so the engine’s starting process can run reliably. The boost pump is designed to provide that initial, pressurized flow, pushing fuel through the start/priming path and into the engine fuel control unit so the engine can light off and begin to run. It also helps guarantee fuel is available even if the main pump isn’t delivering full pressure yet, acting as a reliable backup during start.

The other components have different roles. The XFLOW pump is another type of pump used in the fuel system, but it isn’t the primary source for delivering start fuel in most configurations. The SOV is a shut-off valve that controls fuel flow, not a pump. The ejector pump can aid priming in some layouts, but the standard start fuel supply is provided by the boost pump.