Figure 5-20.-Fuel supply pump assembly-sectional view.
Figure 5-21.-Fuel intake flow diagram.
Figure 5-22.Beginning of fuel delivery flow diagram.
displacement fuel supply pump (fig. 5-20) is gear driven
by the pump camshaft through an engine camshaft gear
and provides fuel to the hydraulic head for injection and
Figure 5-21 shows fuel intake at the hydraulic head.
Injection (fig. 5-22) begins when fuel flows around the
fuel plunger annulus (fig. 5-23) through the open
distributing slot to the injection nozzle. A continued
upward movement of the fuel plunger causes the spill
passage to pass through the plunger sleeve (fig. 5-24).
This reduces pressure, allowing the fuel delivery valve
to close, ending injection. This is accomplished through
a single plunger, multioutlet hydraulic head assembly
Figure 5-23.-Fuel delivery flow diagram.