Pre-Injection

As soon as the engine starts to turn over and the control module receives signals from the crankshaft position sensor, the fuel pump relay operates and all the injectors open simultaneously to squirt in a small amount of fuel via the inlet valves. The opening duration is determined by the coolant temperature.

The purpose of this is to achieve shorter starting times. After this initial injection of fuel the system changes to sequential fuel injection.

When the ignition switch is turned to the ON position, the main relay operates and power is supplied to the injectors.

As soon as the control module perceives that the crankshaft has started to rotate, the fuel pump relay also operates. Shortly afterwards, depending on the coolant temperature, the six injectors open simultaneously. This ensures short starting times.

After this initial injection of fuel the system reverts to sequential fuel injection.

When the ignition switch is turned to the OFF position, the control module is still activated and the main relay remains operated for a certain period of time.

At engine temperatures below -4°C (25°F) this period is 30 seconds and at engine temperatures above -4°C (25°F) it is 5 seconds.

No pre-injection takes place if the engine is restarted during this period.