E46 series BMW 3

since 1998 of release

Repair and car operation

E46 series BMW 3
+ BMW 3 Cars (E46)
+ Current leaving and service
+ Engine
+ Systems of cooling, heating
- Power supply systems, injection and release
   Security measures and rules of observance of purity at work with fuel system
   Removal and installation of the sensor of a stock of fuel / fuel pump
   Check of the sensor of a stock of fuel
   + Power supply system of petrol engines
   - System of injection of fuel of the petrol engine
      The general information and security measures at work
      Principle of work of DME system
      Removal and installation of injectors
      Check of system of injection of the petrol engine
      Check and adjustment of turns of idling and concentration WITH
   + Power supply system of diesel engines
   + 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
+ Body
+ Onboard electric equipment
+ electric equipment Schemes


Principle of work of DME system

Scheme of system of a digital control engine (DME)

1 — an adsorber
2 — the locking valve
3 — the valve of ventilation of a fuel tank
4 — a regulator of pressure of fuel
5 — an injector
6 — a pressure zadatchik
7 — the ignition coil
8 — the situation sensor
9 — the pump of secondary air
10 — the locking valve
11 — a measuring instrument of weight of air
12 — a monitor
13 — the butterfly valve sensor

14 — an idling zadatchik
15 — the air temperature sensor
16 — the valve of a retsirkulyatsiya of the fulfilled gases
17 — the fuel filter
18 — the detonation sensor
19 — the sensor of number of turns
20 — the sensor of temperature of the engine
21 — the oxygen sensor
22 — the diagnostic socket
23 — a diagnostic lamp
24 — the differential sensor of pressure
25 — the fuel pump

Sensors of system of injection of petrol engines





Fuel is sucked in from a fuel tank by the electric gasoline pump located in a fuel tank, and moves via the fuel filter to injectors. The regulator of pressure supports pressure of fuel in system to constants.

Injectors have electric management and inject fuel impulsno into the inlet pipeline in front of inlet valves of the engine.

Air is soaked up by the engine via the air filter and moves through butterfly valve knot, and also the inlet pipeline to inlet valves.

The injected amount of fuel is defined, first of all, by mass of soaked-up air. The mass of soaked-up air is defined by a measuring instrument located in the inlet pipeline. In the case of a measuring instrument of weight there is thin, electricly a warmed-up plate which is cooled with a passable stream of air. The control system changes value of a current of heating so that the temperature of a plate remained a constant. If, for example, the amount of soaked-up air increases, the plate aspires to be cooled. Thereof value of a current of heating of a plate grows. The control system of the engine determines mass of air by deviations of a current of heating and respectively regulates amount of injected fuel.

Information arriving from various sensors, and the teams arriving to executive bodies, provide optimum operation of the engine in any mode. If sensors fail, the monitor is switched in emergency operation to exclude damages of the engine and to provide possibility of further movement of the car. Failure of sensors not necessarily should be felt on deterioration of operation of the engine. However no later than the closest review period of the fulfilled gases data on it will be brought in memory of malfunctions of a control system by the engine.

- Zadatchik of idling operates amount of air idling bypassing a butterfly valve. It provides maintenance of constant number of turns idling irrespective of connection of additional consumers as, for example, the power steering or the cooling compressor.

- Sensors of temperature of cooling liquid and the sensor of temperature of soaked-up air report the current value of temperature as a result of change of resistance of the resistor. At temperature increase resistance decreases.

- The system of ventilation of a fuel tank consists of an adsorber and the locking valve. In an adsorber fuel pairs which are forming as a result of heating of fuel accumulate. At operation of the engine of pair отсысываются from an adsorber also move in chambers of combustion of the engine.

- Sensors of oxygen measure the content of oxygen in the fulfilled gases before and after the catalytic converter and transmit the corresponding signals in the control unit the engine.

- The relay of the fuel pump is in the relay block over a ware box. The relay submits a current to the fuel pump.

- The system of ignition has no the mobile parts, the traditional distributor of ignition is absent. Each spark plug has the coil.

- The monitoring system of tension of ignition at too low voltage disconnects the DME block (for example, owing to cable damage). Thus the engine cannot be started. It excludes damages of the catalytic converter.

- The system of anti-detonation regulation serves for definition and regulation of optimum time of ignition for each cylinder. If there is a malfunction in ignition system, supply of fuel to the corresponding cylinder stops.

- 320i, 323i, 328i: The system of regulation of phases of a gazoraspredeleniye (the moments of opening and closing of inlet and final valves), shortly called Doppel VANOS, turns both camshafts in relation to asterisks on a corner providing optimum phases of a gazoraspredeleniye on any power setting, and consequently optimum idling, high characteristics of a torque and lowered fuel consumption. Turn is carried out under the pressure of oil. For this purpose the DME system via the electrooperated valve regulates pressure of oil in the operating element VANOS.

- The adjustable inlet pipeline depending on number of turns of the engine regulates length of the inlet pipeline. For this purpose in the inlet pipeline the rotary zaslonka with pneumomanagement is established. The big length of the pipeline at low number of turns thanks to a resonance provides good filling of cylinders and by that higher torque. At a large number of turns the length of a soaking-up path decreases that increases engine capacity potential.