BMW 3 Series E46
since 1998 release
Repair and operation of the car
BMW 3 Series E46
+ BMW 3 cars (E46)
+ Current leaving and service
+ Cooling systems, heating
- Power supply systems, injection and release
Security measures and rules of respect for purity during the work with fuel system
Removal and installation of the sensor of a reserve of fuel / fuel pump
Check of the sensor of a reserve of fuel
+ Power supply system of petrol engines
+ System of injection of fuel of the petrol engine
- Power supply system of diesel engines
Principle of operation of the diesel engine
Work of system of injection
Device of heating of the fuel filter
Removal and installation of nozzles
+ System of production of the fulfilled gases
+ Engine electric equipment
+ RKPP and transmission line
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Onboard electric equipment
+ Schemes of electric equipment
Principle of operation of the diesel engineDuring the operation of the diesel engine in its cylinders clean air which contracts to high pressure is soaked up. At the same time air heats up to temperature exceeding temperature of ignition of diesel fuel. Fuel is injected into cylinders where air temperature makes about +600 °C, with some advancing and ignites. Thus, spark plugs for ignition of fuel are not required.
At very cold engine temperature of compression of air can be insufficient for fuel ignition. In this case preliminary heating of the engine is required. For this purpose in each cylinder of the engine the electric glow plug is established. Duration of heating of the engine depends on temperature of external air and is regulated by the special relay of the DDE monitor.
Fuel is sucked in by the toplivopodkachivayushchy pump located in the fuel tank and moves to the fuel pump of high pressure (FPHP). In TNVD fuel compresses up to the pressure necessary for injection. The injection is made as it should be, similar to an ignition order in the petrol engine.
The injection of fuel in cylinders can be made in three ways: via the precamera, the vortex camera or directly in the combustion chamber.
At vortex-chamber and prechamber injection diesel fuel is injected into the precamera of the corresponding cylinder. Hot fuel mix at once ignites. However the volume of the oxygen which is contained in the precamera is sufficient for burning only of a part of the injected fuel. The remained not burned down part of fuel under the influence of pressure of combustion is thrown in the main combustion chamber where there is a full reburning of fuel.
At the direct injection applied in the BMW engine of the 3rd series, TNVD directly injects fuel into the combustion chamber, namely, into a cavity in the piston. At the same time TNVD creates pressure about 1300 bars and injects fuel into two steps. Thanks to mnogosopelny nozzles at first the preliminary injection of a small amount of fuel which, burning down, creates favorable conditions for injection of the main amount of fuel is made. Such process of injection provides the soft and silent combustion similar to vortex-chamber combustion. The amount of injectable fuel is regulated by the electronic monitor.
Before intake of fuel in TNVD it is cleared in the fuel filter of pollution and water. Therefore it is very important regular within carrying out maintenance to clear the fuel filter.
TNVD does not demand service. All mobile details are greased with diesel fuel. The TNVD drive is carried out through a chain.