20921909 Volvo.Penta Charge air pipe

General Information
Engine Design
4.236 Engine
Type ... Four Cylinder, Four StrokeCombustion System ... Direct InjectionNominal Bore ... 98.43 mm (3.875 in)Stroke ... 127 mm (5 in)Cubic Capacity ... 3.86 liters (236 cu in)Compression Ratio ... 16 to 1Number and Arrangement of Cylinders ... 1-4Firing Order ... 1-3-4-2Rotation of crankshaft (as seen from front of engine) ... ClockwiseRotation of camshaft (as seen from front of engine) ... ClockwiseThe left side and right side of engine are as seen from flywheel end. No. 1 cylinder is the front cylinder of the engine.Engine Serial Number
The engine serial number is located on the left hand side of the block above the fuel injection pump.
Engine Serial Number LocationThe first two characters of the serial number stand for the engine family and type. LD stands for a naturally aspirated 4.236 Engine. The next five characters are the parts list number. These five characters are represented by dashes "-" in this module. The next single letter is the country of origin. The next set of numbers is the production serial number, and the last letter is the year of manufacture.Some new components and improvements have been introduced on the 4.236 Engine. If there is a difference in service or specifications, it is noted in this module. The engine cut-in serial numbers are given for the changes if available.Fuel System
Basic Fuel System Diagram (Typical Example)
(1) Fuel Injectors. (2) Fuel return line from injectors. (3) Cold start heater (thermostat). (4) Fuel return line from fuel filter. (5) Fuel return line from injection pump. (6) Fuel supply line to injection pump. (7) Fuel filter. (8) Fuel lift pump. (9) Water separator. (10) Fuel injection pump. (11) High pressure fuel line. (12) Fuel tank.When the engine is turning, fuel is pulled from fuel tank (12) through water separator (9) (not on all models) by fuel lift pump (8). When the fuel goes through the water separator, any water in the fuel will go to bottom of the bowl. The fuel lift pump sends the fuel at a low pressure to fuel filter (7). From the fuel filter, the fuel goes through line (6) to fuel injection pump (10). The fuel injection pump sends high pressure fuel through lines (11) to each fuel injector (1), and the fuel injector sprays fuel into the cylinder. Fuel not used by the injection pump goes through line (5) to the inlet side of fuel filter (7).Leakage from the fuel injectors flows through line (2) to the top of fuel filter (7) and back to fuel tank (12), through line (4).The fuel injection pump needs fuel for lubrication. The precision parts of the pump are easily damaged. For this reason, the engine must NOT be started until the injection pump is full of fuel that is free of air.The system must be primed any time any part of the system is drained of fuel. For example, when the fuel filter is changed or a fuel line is removed, when the inspection cover on the fuel injection pump is removed for service or repair, the fuel system must be primed (air removed).
Fuel System Components (Left Side)
(1) Fuel injector. (2) Fuel return line from injectors. (5) Fuel return line from fuel injection pump. (6) Fuel supply line to fuel injection pump. (7) Fuel filter (attachment point-out of photo). (10) Fuel injection pump. (11) High pressure fuel lines.
Fuel System Components (Right Side)
(8) Fuel lift pump.There is a small screen in fuel lift pump (8). The pump also has a manual lever to prime the fuel system (remove the air). The orifice in the cover of fuel filter (7), to release air in the system, is in the inlet side of the filter. The orifice is connected to the fuel tank by copper return line (4).Cold start heater (3) is installed in the inlet manifold. It is controlled either by a control switch on the dash or by the ignition switch.
Unless there is fuel flow through the valve body of the cold start heater, the unit could be damaged. The fuel supply line to it must also be free of air, or damage could result. A cold start heater, that is damaged, will let fuel drain into the inlet manifold when the engine is running and could cause exhaust smoke.
Fuel Injectors
Fuel Injector
(1) Outlet for return fuel (leakage). (2) Cap nut. (3) Fuel inlet (high pressure) line from fuel injection pump. (4) Lift adjusting screw. (5) Compression spring. (6) Body. (7) Valve spindle. (8) Nozzle cap nut. (9) Needle valve. (10) Nozzle. (11) Orifices (four).Fuel, under high pressure from the fuel injection pump, goes through the hole in fuel inlet (3). The fuel then goes around needle valve (9), fills the inside of nozzle (10) with fuel and pushes against needle valve (9) and compression spring (5). When the force made by the pressure of the fuel is more than the force of spring (5), valve (9) will lift. When needle valve (9) lifts, fuel under high pressure will go through four orifices (11) into the cylinder. When the fuel is sent to the cylinder, the force made by the pressure of the fuel in the nozzle body will become less. The force of spring (5) will then be more than the force of the pressure of the fuel in the nozzle body. Valve (9) will move quickly to the closed position.Needle valve (9) has a close fit with the inside of the nozzle. This makes a positive seal for the valve.When the fuel is sent to the cylinder, a small quantity of fuel will leak by the valve guide. This fuel gives lubrication to the moving parts of the fuel injection nozzle. This fuel then goes through a leak off passage in cap nut (2) to outlet (1) and is returned to the fuel tank.
Fuel Injector
(2) Cap nut. (6) Body. (8) Nozzle cap nut. (10) Nozzle.Fuel Injection Pump
Fuel Injection Pump Components With Mechanical Governor And Electrical Shutoff
(1) Fuel return passage