PRINCIPLES GASOLINE/DIESEL FUEL SYSTEMS - OD1620 - LESSON 2/TASK 2
FIGURE 57. PLUNGERTYPE SUPPLY PUMP.
(a) The plunger follows the camshaft by the force of its plunger
spring. As the follower comes off the high point of the cam lobes, the
plunger moves toward the retracted position. This plunger movement creates
a suction in the pump chamber, causing fuel to enter through the inlet valve
(b) As the cam lobe comes around again, it forces the plunger
upward. This forces the fuel out of the chamber through the outlet valve
and to the injection pump.