Fuel injection system — design description (BMW X5 E53)

The engines are equipped with a comprehensive control system – an electronic type KSUD, a more advanced modification (M7.2), compared to the KSUD on the M54 engine.

Data for verification and adjustment

The engine crankshaft speed at idle is 750–850 min⁻¹.

The carbon monoxide (CO) content in the exhaust gas is automatically maintained within specified limits. In the event of misfire in one of the cylinders due to a malfunction of the primary winding circuit of the ignition coil, the ECU-KUD switches off the injector of this cylinder, which prevents the neutralizer from failing due to a large amount of unburned working mixture getting into it. The engine has two sensors for measuring the oxygen concentration in the exhaust gas. One in front of the neutralizer, which acts as a regulator, the second, after the neutralizer, monitors its operation. A total of two neutralizers are installed, for cylinders 1–4 and for cylinders 5–8.

Carbon monoxide (CO) content in exhaust gas:

• with exhaust gas neutralizer 0.2 – 0.12%;
• without exhaust catalyst 0.5 – 1.5%.

Distribution main

The distribution main is a tubular cavity of a "U" shape with sockets (holes) for installing injectors, fuel supply and outlet fittings (Fig. 4.19).



The distribution line functions as a pressure accumulator and ensures the supply of fuel under the same pressure to the injectors. Its volume is specially calculated to ensure noise reduction when changing operating modes and pressure drops.

[The original text is available on the website BMWMAN.RU]