32370-ZY6-003 Honda BOX ASSY., JUNCTION

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Fuel system schematic of 3066 Engine (1) Secondary fuel filter (2) Fuel supply for fuel injection nozzle (3) Fuel injection nozzle (4) Supply line for the secondary fuel filter (5) Fuel tank (6) Valve for the fuel return (7) Fuel injection pump (8) Fuel transfer pump (9) Fuel return lineFuel transfer pump (8) is driven by the camshaft. Fuel transfer pump (8) pulls fuel from fuel tank (5). The fuel transfer pump (8) supplies fuel to secondary fuel filter (1). Fuel is supplied to the fuel filter at a pressure of 176 to 245 kPa (25.5 to 35.5 psi). The filtered fuel is sent to the fuel chamber in the fuel injection pump housing.The fuel pump plunger is raised by the rotation of the camshaft. The fuel injection pump (7) delivers fuel through the supply line (4) to the secondary fuel filter (1). Fuel is then supplied to the fuel injection nozzle (3). The fuel is then injected into the engine cylinder.At least two times the quantity of fuel that is needed is delivered to the fuel injection pump (7) by the fuel transfer pump (8). A valve for the fuel return (9) is installed in order to return the excess fuel to fuel tank (5). The fuel pressure must exceed a set value in order for the fuel to return to the fuel tank.Note: The fuel lubricates the inside of the holder for the fuel injection nozzle.Fuel Injection Pump Operation
Illustration 2 g00534572
View of cross section of fuel injection pump (1) Spring for delivery valve (2) Delivery valve (3) Plunger barrel (4) Chamber for fuel (5) Plunger (6) Control pinion (7) Control sleeve (8) Injection control rack (9) Upper spring seat (10) Plunger spring (11) Lower spring seat (12) Adjusting bolt for tappet (13) Tappet (14) CamshaftThe plunger movement is constant. The plunger is raised by tappet (13) and returned by plunger spring (10) through engine rotation. The chamber for fuel (4) of the housing for the pump is always filled with fuel. The suction and the discharge port of plunger barrel (3) opens to the chamber for fuel.Fuel is delivered to plunger barrel (3) when plunger (5) descends. The suction of fuel is complete when plunger (5) reaches the lowest point. Plunger (5) then ascends. The suction and discharge ports of plunger barrel (3) is closed by plunger (5). The fuel pressure then increases. When the fuel pressure reaches approximately 820 kPa (119 psi) the delivery valve is forced upward. Fuel is then delivered to the fuel injection nozzle through the pipe for the fuel injector.
Illustration 3 g00534776
Cutaway view of fuel injection pump (1) Spring for delivery valve (2) Delivery valve (4) Chamber for fuel (5) Plunger (6) Control pinion (7) Control sleeve (8) Injection control rack (10) Plunger spring (13) Tappet (14) Camshaft (15) Delivery valve holder (16) Suction and discharge port
Illustration 4 g00534857
Effective stroke of the plunger (3) Plunger barrel (5) Plunger (16) Suction and discharge port (17) Plunger helix (A) Start of delivery (B) End of deliveryPlunger (5) ascends further. The delivery of fuel and the spray of the fuel injector ends when the helix of the plunger (17) meets the suction and discharge port (16) of the plunger barrel (3). The spring for the delivery valve closes the delivery valve and fuel is no longer delivered. Plunger (5) ascends further. The effective stroke is altered and the amount of fuel that is delivered is changed if plunger (5) is rotated.Mechanisms for Rotating Plunger
Illustration 5 g00534859
Mechanisms for rotating the Plunger (A) No delivery (B) Partial delivery (C) Maximum deliveryThe flange at the lower portion of the plunger is inserted into the groove of the control sleeve. The teeth on the upper portion of the control sleeve are engaged with the teeth of the injection control rack. The plunger is then rotated with the injection control rack. The quantity of fuel that is delivered is dependent on movement of the injection control rack.Assembly of Delivery Valve
Illustration 6 g00534860
Assembly of Delivery Valve (1) Spring for delivery valve (2) Delivery valve (3) Seat (4) Piston (5) Retraction strokeDelivery valve (2) delivers high pressure fuel to the fuel injection nozzle through the fuel injection line. Delivery valve (2) prevents reverse flow of fuel from the fuel injection line to the plunger barrel. The prevention of reverse flow occurs after the plunger finishes the delivery of fuel. The fuel pressure inside the fuel injection line is reduced by the action of absorption of piston (4) when delivery valve (2) descends. The fuel pressure is reduced in order to prevent leakage of fuel after the fuel injection nozzle is closed.Tappet Assembly
Illustration 7 g00534861
Tappet assembly (1) Adjusting bolt (2) Locknut (3) Body of tappet (4) Guide (5) Roller (6) Roller bushing (7) Roller pinThe tappet assembly is designed to change rotary motion of the camshaft into reciprocating motion. The plunger is lowered and the plunger is raised by the rotation of the camshaft. The timing of the injection pump is also regulated by the rotation of the camshaft.Fuel Transfer Pump