PRINCIPLES GASOLINE/DIESEL FUEL SYSTEMS - OD1620 - LESSON 2/TASK 2
eliminates the need for unittype injectors and the associated linkage and
camshafts, making the system less cumbersome. The injectors are of the same
basic design as the ones used in the multiple unit injection system. The
nozzles usually are of the holetype.
FIGURE 55. PSB DISTRIBUTOR INJECTION SYSTEM.
(2) The PSB Injector Pump. The PSB injection pump is compact and
selfcontained, housing all components of the injectors. Operation is shown
in figure 56 on the following page.
(a) The PSB pump contains a plungertype pump that creates the
highpressure fuel charges for the injectors. The pump is driven by a
camshaft that is contained within the PBS unit. Fuel is delivered to the
PBS pump from the fuel tank by the fuel delivery pump at a regulated
pressure of approximately 20 psi. The low pressure fuel supply enters the
pump chamber through the inlet port when the plunger is retracted fully. As