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 cooling.

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 (fig. 5-19).

Figure 5-23.-Fuel delivery flow diagram.