21052971 Volvo.Penta Cable tie

Fuel System
Engines With Serial Numbers 90N1-90N6120
Schematic Of Fuel System
(1) Return line for fuel injection nozzles. (2) Fuel priming pump. (3) Return line for constant purge valve. (4) Constant purge valve. (5) Manual purge valve. (6) Fuel injection nozzle. (7) Fuel tank. (8) Fuel inlet line. (9) Fuel filter. (10) Bypass valve (for fuel priming pump). (11) Fuel transfer pump. (12) Fuel bypass valve. (13) Camshaft. (14) Fuel injection pump housing. (A) Check valve. (B) Check valve. (C) Check valve. (D) Check valve.The sleeve metering fuel system is a pressure type fuel system. The name for the fuel system is from the method used to control the amount of fuel sent to the cylinders. This fuel system has an fuel injection pump for each cylinder of the engine. It also has a fuel transfer pump on the front of the fuel injection pump housing. The governor is on the rear of the fuel injection pump housing.The drive gear for the fuel transfer pump is on the front of the camshaft for the fuel injection pumps. The carrier for the governor weights is bolted to the rear of the camshaft for the fuel injection pumps. The fuel injection pump housing has a bearing at each end to support the camshaft. The camshaft for the sleeve metering fuel system is driven by the timing gears at the front of the engine.The fuel injection pumps, lifters and rollers, and the camshaft are all inside of the fuel injection pump housing. The fuel injection pump housing and the governor housing are full of fuel at transfer pump pressure (fuel system pressure).
Diesel fuel is the only lubrication for the moving parts in the transfer pump, fuel injection pump housing and the governor. The fuel injection pump housing must be full of fuel before turning the camshaft.
This fuel system has governor weights, a thrust collar and two governor springs. One governor spring is for high idle and the other governor spring is for low idle. Rotation of the shaft for governor control, compression of the governor springs, movement of connecting linkage in the governor and fuel injection pump housing controls the amount of fuel sent to the engine cylinders.
Cross Section Of Fuel System
(11) Fuel transfer pump. (13) Camshaft. (14) Fuel injection pump housing. (15) Lever. (16) Governor housing. (17) Load stop pin. (18) Cover. (19) Sleeve control shafts (two). (20) Inside fuel passage. (21) Drive gear for fuel transfer pump. (22) Lever on governor shaft. (23) Governor springs (inner spring is for low idle: outer spring is for high idle). (24) Spring seat. (25) Thrust collar. (26) Overfuel spring. (27) Load stop lever. (28) Carrier and governor weights. (29) Sleeve levers.
Fuel System Components
(14) Fuel injection pump housing. (19) Sleeve control shafts. (29) Sleeve levers. (30) Sleeves.Fuel from fuel tank (7) is pulled by fuel transfer pump (11) through fuel filter (9). From fuel filter (9) the fuel goes to the fuel injection pump housing (14). The fuel goes in fuel injection pump housing (14) at the top and goes through inside passage (20) to fuel transfer pump (11).From fuel transfer pump (11), fuel under pressure, fills the fuel injection pump housing (14). Pressure of the fuel in the fuel injection pump housing (14) is controlled by bypass valve (12). Pressure of the fuel at Full Load is 205 35 kPa (30 5 psi). If the pressure of fuel in the fuel injection pump housing (14) gets too high, bypass valve (12) will move (open) to let some of the fuel return to the inlet of fuel transfer pump (11).Lever (15) for the governor is connected by linkage and governor springs (23) to the sleeve control shafts (19). Any movement of lever (22) will cause a change in the position of sleeve control shafts (19).When lever (15) is moved to give more fuel to the engine, lever (22) will put governor springs (23) in compression and move thrust collar (25) forward. As thrust collar (25) moves forward, the connecting linkage will cause sleeve control shafts (19) to turn. With this movement of the sleeve control shafts, levers (29) will lift sleeves (30) to make an increase in the amount of fuel sent to the engine cylinders.When starting the engine, the force of overfuel spring (26) is enough to push thrust collar (25) to the full fuel position. This lets the engine have the maximum amount of fuel for injection when starting. At approximately 400 rpm, carrier and governor weights (28) make enough force to push overfuel spring (26) together. Thrust collar (25) and spring seat (24) come into contact. From this time on, the governor works to control the speed of the engine.When governor springs (23) are put in compression, the spring seat at the front of the governor springs will make contact with load stop lever (27). Rotation of the load stop lever moves load stop pin (17) up until the load stop pin comes in contact with the stop bar or stop screw. This stops the movement of thrust collar (25), the connecting levers, and sleeve control shafts (19). At this position, the maximum amount of fuel per stroke is being injected by each fuel injection pump.The carrier and governor weights (28) is held on the rear of camshaft (13) by bolts. When engine rpm goes up, fuel injection pump camshaft (13) turns faster. Any change of camshaft rpm will change the rpm and position of carrier and governor weights (28). Any change of governor weight position will cause thrust collar (25) to move. As carrier and governor weights (28) turn faster, thrust collar (25) is pushed toward governor springs (23). When the force of governor springs (23) is balanced by the centrifugal force of the governor weights, sleeves (30) of the fuel injection pumps are held at a specific position to send a specific amount of fuel to the engine cylinders.When the governor control lever is turned toward the Fuel-Off position with the engine running, there is a reduction of force