GF07.08-P-3000D | Start quantity control, function | 8.1.09 |
ENGINE 271.942 in MODEL 203 up to model year 2008 /AEJ 07
ENGINE 271.942 in MODEL 209
P07.70-2027-06
18 Rail
20 High-pressure pump
B4/6 Rail pressure sensor
B11/4 Coolant temperature sensor
L5 Crankshaft position sensor
M16/6 Throttle valve actuator
N3/10 ME-SFI [ME] control unit
N10/1 Front SAM control unit with fuse and relay module
Y74 Pressure control valve
Y76 Fuel injectors
In order to facilitate starting of a cold engine, fuel must also be injected during the starting procedure.
The increased injection quantity (start quantity) is achieved by extending the injection time.
The start quantity is dependent on:
Coolant temperature
Engine speed
Engine off time
The start quantity control is enabled after start recognition. It remains activated until a temperature-related engine speed is exceeded.
The higher the coolant temperature, the lower is the start quantity enable by the ME-SFI [ME] control unit.
The injected fuel quantity is determined by the opening times of the fuel injectors and the rail pressure.
The opening times of the fuel injectors are dependent on the battery voltage. In order to guarantee the start quantity at a low battery voltage, the ME control unit extends the opening times.
Depending on the coolant temperature the initial fuel injection is not performed until the rail pressure is 50 to 80 bar.
After engine start, the rail pressure is controlled between approx. 30 and 120 bar in accordance with the particular operating conditions.
High pressure pump, location/task/design/function | 20 | ||
Rail, location/task/design/function | 18 | ||
Fuel injectors, location/task/design/function | Y76 | ||
Crankshaft position sensor, location/task/design/function | L5 | ||
Coolant temperature sensor, location/task/design/function | B11/4 | ||
Rail pressure sensor, location/task/design/function | B4/6 | ||
Pressure regulator valve, location/task/design/function | Y74 | ||
ME-SFI control unit, location/task/design/function | N3/10 | ||
Throttle valve actuator, location/task/design/function | M16/6 |
Referenced documents
- gf0702p2101d High pressure pump, location/task/design/function
- gf0703p2101d Rail - location/task/design/function
- gf0703p2103d Fuel injectors - location/task/design/function
- gf0704p4116d Crankshaft position sensor - location/task/design/function
- gf0704p5026d Coolant temperature sensor - location/task/design/function
- gf0704p5044d Rail pressure sensor - location/task/design/function
- gf0705p2101d Pressure regulator valve, location/task/design/function
- gf0761p5000ke ME-SFI control unit, location/task/design/function
- gf3022p4101ke Throttle valve actuator, location/task/design/function