The Robert Bosch Verteiler diesel injection pump has a metering plunger and a distributor mechanism that sends fuel to the correct cylinder. The pump varies the injection timing in response to the engine's revolutions, and a cold start mechanism advances the idle timing manually.
Contrary to inline pumps, a Bosch VE pump has only one metering plunger. The plunger in a Bosch VE pump rotates around its axis to send fuel to the right cylinder and perform the metering function. Through an in-and-out reciprocating translation, the plunger produces a high-pressure pumping action.
The pump consists of a drive shaft, cam plate and driving disk connected together, all of which rotate at the same time with the plunger. For each revolution made by the drive shaft, the plunger pumps four times. Additionally, the drive shaft drives the fuel-supply pump and governor flyweight drive gear.
A Bosch VE pump regulates the delivery of fuel by spilling some fuel through spill ports as opposed to changing the mechanical stroke. At a particular angle of the drive shaft's rotation, the mechanism exposes a spill port under a control sleeve. The pump has four delivery valves that deliver fuel to the correct cylinder after every 90 degrees of the plunger's rotation.