The diesel fuel injection pump delivers tightly controlled amounts of diesel fuel into the cylinders of the engine or the prechambers of the cylinders. The pumps are driven by plungers that, through translation, meters the fuel before it is injected.
The mechanical action of the diesel fuel injection pump creates a highly precise system that prevents flooding and other mechanical failures. The engine's plungers fire four times during a rotation, making circular connections with the delivery valves on the intake.
Diesel fuel injection pumps come in two varieties, one with a single metering plunger and a distributor. The second type of pump is an inline pump with a plunger for each cylinder.