What component ensures fuel pressure to engine-driven pumps during low tank pressure or start?

• A. Crossfeed valve
• B. Engine-driven pump
• C. Boost pump
• D. Fuel filter

Answer: (C)

When starting or when tank pressure is low, fuel must be primed to the engine-driven pumps. The boost pump provides positive pressure from the tank to the engine-driven pump, ensuring a reliable flow and preventing cavitation so the engine can start and continue receiving fuel. Crossfeed valves serve to balance or transfer fuel between tanks, not to guarantee pressure to the engine-driven pumps during start. The engine-driven pump itself supplies pressure during normal operation, but it relies on the boost pump to furnish initial pressure when tank pressure is insufficient. The fuel filter’s job is to remove contaminants, not to pressurize the system.