BMW 3 Series E30
since 1983-1994 release
Repair and operation of the car
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
- 6. Fuel system
6.3. Check of system of injection
6.4. Air stream measuring instrument
6.5. Throttle branch pipe
6.6. Fuel pressure regulator
6.7. Nozzle of launch of the cold engine and thermotimer
6.8. Check and replacement of nozzles
6.9. Air proofreader of idling
6.10. Order of a decompression of fuel system
6.11. Check of pressure of fuel
6.12. The fuel pump, the pump of pumping and the fuel level sensor in a tank
6.13. Fuel pipes and union
6.14. Fuel tank
6.15. Air filter
6.16. Cable of the drive of a butterfly valve
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Useful tips
The considered cars are equipped with system of injection of fuel, except models 316 on which Solex 2B4 carburetors (cars of early release) and Solex 2BE (later release) are installed. The fuel pump of carburetor engines mechanical, with the cam drive from a cam-shaft.
System of injection like L-Jetronic or Motronic. Since 1988 cars are equipped with the advanced Motronic system in which there is no nozzle for launch of the cold engine. The electric fuel pump is mounted or in a back part of the car, on the body bottom (on early models), or in the fuel tank. In the Motronic system of the relay of injection works from a signal from the control unit (ECU block). At inclusion of ignition the fuel pump works within several seconds and is switched-off only after a full stop of the engine. On early models the pump of pumping of low pressure mounted in the fuel tank and which is switched on consistently with the main pump is provided. The main pump provides maintenance of necessary pressure of fuel. Maintenance of constant pressure at the time of injection is provided with the regulator of pressure and a suppressor of pulsations of pressure (the last is mounted about the fuel filter).
The system of injection of fuel of the considered cars consists of 3 subsystems – fuel, an intake of air and the processor control unit.
The fuel pump provides supply of fuel via the filter in the distributor under constant pressure. Stabilization of pressure of fuel at the exit of the distributor is provided with pressure regulator.
System of an intake of air
Consists of the air cleaner, the measuring instrument of a stream of air, a throttle branch pipe, the soaking-up collector and the connecting hoses and branch pipes. The measuring instrument of a stream of air of bladed type, a consumption of air is proportional to the angle of rotation of the gate and resistance of a potentiometer which are rigidly connected with a gate axis.
Electronic control unit
On the car the electronic control unit (ECU) which provides automatic adjustment of the moment of ignition and also quantity and composition of fuel-air mix according to information from various sensors tracing power setting is established. The structure of auxiliary elements of system (sensors, switches, etc.) is defined by a concrete type of the applied system of injection.
The applied systems of injection
System of injection like L-Jetronic of Bosch (till 1987)
System of injection L-Jetronic
System odnoforsunochny with an electromagnetic nozzle. The basic adjustable parameters are duration of an open condition of nozzles (amount of injectable fuel) and idling turns. Auxiliary elements of system are the sensor of temperature of cooling liquid, the switch of a butterfly valve, the idling stabilizer (perepuskny the air valve), the relay and safety locks.
System of injection like Motronic
System of injection Motronic
System mnogoforsunochny with electromagnetic nozzles. Adjustable parameters are the amount of injectable fuel, the ignition moment, turns of idling and composition of exhaust gases.