CITROEN C1 - Page 106

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INJECTION
OPERATING PHASES : BOSCH ME 7.9.5 INJECTION SYSTEM
Engine : CFA
Air supply function
Motorised butterfly housing for MMT piloted manual gearbox.
The torque requested by the injection ECU determines an angle of opening of the butterfly:
The angle of opening of the butterfly varies with the demand coming from the driver.
Engine load is commanded by the butterfly housing.
Injection function :
The quantity of fuel to be injected is calculated from the following parameters :
- Position of the accelerator pedal
- Point of engine operation (engine speed, temperatures, pressures)
As a function of the quantity of fuel to be injected, the injection ECU determines the following parameters :
- Start of injection
- Time of injection
The injection ECU draws on the specific strategies for starting and stopping of the engine.
Determination of the quantity of fuel to be injected
The quantity of fuel to be injected is calculated from the demand coming from the driver, provided by the position of the accelerator pedal.
To determine the quantity of fuel to be injected, the injection ECU takes account of the following elements:
- Demand from the driver (after filtering)
- Quantity of air entering the engine (calculation)
The quantity of fuel to be injected is transformed into an injection time.
Cut-off in deceleration
During deceleration with the engine hot, gas butterfly closed (foot off), the injection of fuel is cut off in order to :
- Reduce fuel consumption
- Minimise pollution
- Prevent the temperature of the catalytic converter from rising
FR-C1-page93-125-2005 9/01/06 8:51 Page 100