Fuel injection

During fully sequential fuel injection, each injector is controlled by means of its own final stage.

Fully sequential fuel injection has the following advantages:

• Improved fuel preparation for each individual cylinder
• Adaptation of the fuel injection timing to suit the engine's operating condition (engine speed, load, engine temperature)
• Cylinder-selective correction of injected fuel quantity for varying load (during a cycle, the fuel injection timing can be corrected by extending or shortening it)
• Cylinder-selective cutoff (e.g. when an ignition coil is defective)
• Diagnosis for each individual injector possible

The control of each injector by means of its own individual final stage achieves a fuel build-up which is the same in all cylinders. This ensures a uniformly-effective fuel preparation throughout.

The fuel build-up time is variable and depends on the load, engine speed and engine temperature.

As it is only injected once per camshaft rotation, the spread of fuel due to tolerances in the components is reduced.

In addition, the idle-running performance is improved as the response and dropout times at the injectors are reduced.

Moreover, a marginal reduction in fuel consumption is also achieved.

When the vehicle is in motion and there is a sudden acceleration or the throttle is closed, the fuel injection period can be adjusted. If the injectors are still open, the mixture at every valve can be adjusted by extending or shortening the fuel injection period. This achieves an improved engine response.