: Uses a single pumping element and a rotor to distribute fuel to all cylinders in sequence, typically found in smaller vehicles.
: To stop injection, a helical groove on the plunger eventually uncovers a spill port . This allows pressurized fuel to "spill" back into the lower-pressure gallery, causing the delivery valve to close instantly. Fuel Injection pump working principle - Animation
: Driven by the engine's camshaft, the plunger moves upward. Once it covers the barrel ports, the trapped fuel begins to compress. : Uses a single pumping element and a
: When the pressure is high enough to overcome the spring force of the delivery valve , it snaps open, sending a high-pressure pulse of fuel through the lines to the injectors. : Driven by the engine's camshaft, the plunger moves upward
The primary working principle of a fuel injection pump involves using a reciprocating inside a barrel to pressurize and meter fuel before delivering it to the engine cylinders . In a standard mechanical setup, a camshaft drives the plunger up and down, while a control rack rotates the plunger to adjust how much fuel is injected per stroke.
Watch these animations to see how different fuel injection pump types, such as inline and distributor models, move and meter fuel in real-time: Fuel injection pump animation YouTube · MECHANICAL ENGINEERING WORLD
The difference between and indirect injection nozzles.