Operation Of The Supply Pump - Denso 4D56 Service Manual

Operation Section
1 9
–
Plunger A
Ring Cam
Feed Pump
Plunger B
Q001234E

3.5 Operation of the Supply Pump

As shown in the illustration below, the rotation of the eccentric cam causes the ring cam to push Plunger A upwards. Due to the spring
force, Plunger B is pulled in the opposite direction to Plunger A. As a result, Plunger B draws in fuel, while Plunger A pumps it to the
rail.