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INJECTION
OPERATING PHASES : BOSCH ME 7.9.5 INJECTION SYSTEM
Engine : CFA
Engine management
The engine ECU manages the injection on the basis of the information on engine torque :
The engine ECU calculates the need for engine torque from the accelerator pedal sensor
The engine torque requested takes account of various corrections
The engine torque requested is obtained by acting on the following components :
- Butterfly angle (motorised butterfly housing)
- Ignition advance (knock regulation)
- Injection time
Cycle of ignition and injection
Sequential injection: the injectors are commanded separately in the order of injection (3-2-1), just prior to the inlet phase.
Static ignition: one coil per cylinder.
The ECU manages the injection and the ignition simultaneously (metering of the petrol/air mixture).
The quantity of fuel injected is proportional to the time of opening of the injectors which is determined as a function of 3 main parameters :
- Engine load
- Speed of rotation of the engine (TDC sensor)
- The information from the oxygen sensor
Numerous other corrections are also applied during operation, in order to take account of the variations :
- In the heat status of the engine (coolant temperature sensor)
- In the operating conditions (idle phase, stable phase, full load phase, transitory engine speed phases, injection cut-off phase)
- In the atmospheric pressure (altimetric correction)
Injection.
Correction of starting : engine cold
The injection ECU corrects the flow from the injectors during the action of the starter motor.
This quantity is injected in asynchronous mode, thus constant in time, depending only on the temperature of the coolant fluid.
The engine once started receives an injected quantity, synchronous with the ignition which varies in permanence with its thermal evolution.
FR-C1-page93-125-2005 9/01/06 8:51 Page 98
