A high pressure pump draws fluid from a fluid inlet into a compression
chamber through an inlet chamber. The high pressure pump has a fluid
chamber that communicates with the fluid inlet via the inlet chamber. The
high pressure pump includes a plunger and a cylinder. The plunger draws
fluid from the inlet chamber into the compression chamber when the
plunger moves in a drawing direction. The plunger is capable of
pressurizing fluid in the compression chamber when the plunger moves in a
pressurizing direction. The cylinder movably supports the plunger
therein. When the plunger moves in the drawing direction, fluid in the
inlet chamber is drawn into the compression chamber, so that fluid flows
from the fluid chamber into the inlet chamber.