4.14. Systems of injection of fuel

System of injection of L-Jetronic fuel

The system of injection of Bosch L-Jetronic fuel was applied on the majority of the E28 models ("an old sample"). In this fuel system of injection with electronic control it is used on each cylinder on one solenoidal injector. The system copes the Electronic control unit (ECU) which processes information obtained from various sensors and further makes an exact dosage of fuel for cylinders, regulating time of an open condition of an injector. The electric fuel pump through lines of supply of fuel and the filter which is built in the line provides giving under the high pressure of fuel to injectors. The regulator of pressure provides supply of fuel under optimum pressure, allowing pressure to fall and increase depending on turns and loading of the engine. All surplus of fuel on a separate line comes back in the fuel tank.

The sensor continuously measures amount of the arriving air, and ECU for receiving an optimum ratio of mix in an air admission air duct air / fuel regulates fuel mix.

Other components which are a part of system are the throttle valve (which operates an air stream), the cooler temperature sensor, the sensor of provision of a throttle, the valve of stabilization of turns of idling (which for stabilization of turns of idling takes away air, passing the throttle valve) and the related relays and safety locks.

System of injection of Motronic fuel

The Motronic system unites in one block management of fuel of system of injection of L-Jetronic with management of the ignition moment, turns of idling and release.

Functions of management of injection of fuel and turns of idling are similar to the functions of the L-Jetronic system described above. For additional data on the Motronic system address the Head of the Control system of the engine and decrease in toxicity of the fulfilled gases.

The oxygen sensor on late models with the catalytic converter is installed in system of release, This sensor continuously measures the content in the fulfilled gases concentration of oxygen. This information is used by ECU for adjustment of duration of injection, giving an opportunity to establish composition of fuel mix for optimum efficiency of the converter and a minimum of toxicity.