Schematic diagram
Key
- "A" electrical links
- "B" fuel in the tank
- "C" fuel system
| reference | designation | electrical diagram correspondence |
|---|---|---|
| (1) | engine fuse and relay box | BFRM |
| (2) | built-in systems interface | BSI1 |
| (3) | engine ECU | 1320 |
| (4) | petrol injectors (1); (2); (3); (4) | (1331, 1332, 1333, 1334) |
| (5) | petrol injector supply rail | - |
| (6) | pump, gauge and fuel pressure regulator assembly | 1211 |
| "a" | valve SCHRAEDER | - |
Control of the injection
The engine ECU receives and converts the demands from the driver, or from the vehicle (ABS, ESP, automatic gearbox), into information on the necessary torque that is required of the engine
The engine ECU determines the quantity of fuel that is necessary to provide the engine torque that is required
To comply with the emission standards, limit the combustion noises and improve the driving performance, the engine ECU determines the time for each injection of fuel during an engine cycle
Fuel injection time
General
Fuel injection pressure being equal, a longer (or shorter) injection time allows more (or less) fuel to be injected
When there is a large engine load need, fuel injection pressure being equal, the fuel injection time is extended to obtain the maximum engine torque
The fuel injection time corresponds to the time during which the engine ECU commands the fuel injectors to be open
Specificities
The fuel injection time is calculated as a function of the following parameters
- Engine speed
- Engine load
- Vehicle speed
- Engine coolant temperature
- Intake air temperature
- Position of the inlet valves
- Position of the camshaft dephasers
The table below gives an example of the variations in the injection time in relation to the engine speed in the maximum accelerator position
| engine speed | 1300 rpm | 2700 rpm | 4000 rpm | 5000 rpm | 5500 rpm |
|---|---|---|---|---|---|
| injection time | 13 ± 1,5 ms | 14 ± 1,5 ms | 14,5 ± 1,5 ms | 14,5 ± 1,5 ms | 15 ± 1,5 ms |
Fuel supply cut-off
When a pyrotechnic component is triggered, supply of the fuel pump is cut off by the engine relay fusebox (BFRM) via the triggering information coming from the airbag ECU
To restart the engine following a fuel supply cut-off
- Switch off the ignition
- Switch on the ignition
- Start the engine