850308 Mercury PROPELLER SHAFT

Illustration 1 g03842226
(1) Engine ECM
(2) High Pressure Fuel Pump
(3) Common Rail Manifold
(4) Injectors The fuel system is a common rail fuel system. This common rail system not only complies with strict emission regulations the system enables multiple, high-pressure injections that do not vary with engine RPM.The system is an electronically controlled fuel injection device with a high-pressure fuel pump (2) that pressurizes the fuel rail manifold (3). The ECM controls the amount from the injectors, the timing of injection and the pressure in the common rail manifold. This results in fuel always being injected under ideal conditions, which suppresses the hallmark of a diesel engine, the black smoke during takeoff and acceleration. So there is less smoke, cleaner with a higher output of power.High Pressure Fuel Pump
Illustration 2 g03842290
(1) PCV (Pre-Stroke Control Valve)
Illustration 3 g03842303
(1) PCV (Pre-Stroke Control Valve)
(2) Housing
(3) Camshaft
(4) Delivery Valve
(5) Plunger
(6) Tappet
(7) Feed Pump
(8) Cam The supply pump is equivalent to previously used injection pumps and the pump delivers fuel to the rail at a pressure more than double that of previous pumps. The supply pump consists of a feed pump (7), a PCV (Pre-Stroke Control Valve) (1), and a delivery valve (8).Feed Pump
Illustration 4 g03842329
(1) Outer Rotor
(2) Inner Rotor
(3) Suction Port
(4) Discharge port
(5) Camshaft The feed pump sucks up fuel filtered by the fuel filter and supplies fuel to the pump unit. The feed pump is a Trochoid pump with an inner rotor (2) and an outer rotor (1), geared elliptically, the inner rotor is driven by the camshaft (5) and drives the outer rotor in the same direction. In the process, the volume of the part enclosed by the teeth of the rotor changes and pumps the fuel.PCV (Pre-Stroke Control Valve)
Illustration 5 g03842362
(1) Solenoid
(2) Armature
(3) Pushrod The PCV adjusts the amount of fuel discharged from the supply pump to adjust rail pressure. The amount of fuel discharged from the supply pump to the rail is determined by the energize timing of the PCV.The valve is opened and closed by the ON/OFF of energizing the PCV, which is controlled by the Engine ECM. The ON/OFF timing is controlled based on signals from various sensors to provide optimal rail pressure.Delivery Valve
Illustration 6 g03842520
(1) Element
(2) Check ball
(3) Spring
(4) Holder
(5) Plunger The delivery valve location is shown in Illustration 6 and is composed of a check ball, spring, and holder.When the pressure on the plunger side equals/exceeds the pressure on the rail side, the check ball opens and discharges fuel. As soon as the fuel pressure feed is complete, the check ball is pressed back by the spring, and when the check ball touches the seat of the element, cuts off the rail side from the plunger side, thus preventing any backflow of fuel.Fuel Pump Operation
Illustration 7 g03842303
(1) PCV (Pre-Stroke Control Valve)
(2) Housing
(3) Camshaft
(4) Delivery Valve
(5) Plunger
(6) Tappet
(7) Feed Pump
(8) Cam
Illustration 8 g03842484
(1) PCV (Pre-Stroke Control Valve)
(2) Housing
(3) Camshaft
(4) Delivery Valve
(5) Plunger
(7) Feed Pump
(8) Cam
(9) Plunger Chamber
(A) Suction Stroke
(B) Pre-Stroke
(C) From Fuel Filter
(D) To Fuel Return
(E) Compression Start Stroke
(F) Pressure Feed Stroke
(G) To Fuel Rail Manifold The pump unit works to increase the pressure of fuel received from the PCV and is composed of a camshaft (3), tappet (6), and plunger (5). When the camshaft (3) rotates, the cam (8) rotates eccentrically and the tappet (6) is driven up and down by it, which operates the plunger (5) through their cycles.
A: Suction Stroke- The PCV is opened when the plunger falls and fuel is suctioned into the plunger chamber via PCV.
B: Pre-Stroke- Even after the plunger enters the raise process, fuel suctioned passes through the PCV, and is discharged without being pressurized while the PCV is not energized and the valve is open.
E: Compression Start Stroke- The PCV is energized which closes off the passages from the fuel filter (C) and the fuel return (D). The cam rotation moves the plunger upward which increases the fuel pressure to the delivery valve (4).
F: Pressure Feed Stroke- When the PCV is energized and the valve opened based on timing suitable for the amount of fuel needed, the return path is closed by the PCV and the fuel inside the plunger chamber is pressurized. This opens the delivery valve and fuel is fed into the rail.The discharge amount is based on the lift distance of the plunger after the PCV valve closes.Changing of the PCV valve close timing changes the amount discharged, thus controlling rail pressure.Fuel R