GF07.10-P-1004MAW Injection Regulation, Function

GF07.10-P-1004MAW Injection Regulation, Function
ENGINES 156.9 in MODEL 204.0 /2 /3, 212.0 /2

Function requirements for injection regulation, general points
^ Circuit 87M (engine timing ON)
^ Engine running

Injection regulation, general points
The engine receives the fuel quantity allocated in each case by the ME-SFI [ME] control unit (N3/10).
Using the characteristics map, the ME-SFI [ME] control unit computes the injection time according to the following sensors and signals:
- LH and RH hot film MAF sensor (B2/6, B2/7), engine load
- Fuel pressure sensor (B4/15)
- LH and RH intake camshaft Hall sensor (B6/4, B6/5), intake camshaft positions
- LH and RH exhaust camshaft Hall sensor (B6/6, B6/7), exhaust camshaft positions
- Coolant temperature sensor (B11/4)
- Intake air temperature sensor (B17) (in warm-up only)
- Pressure sensor (B28), intake manifold air pressure
- Accelerator pedal sensor (B37), driver engine load request
- Accelerator pedal sensor, accelerator pedal operation fast or slow (when acceleration)
- Crankshaft Hall sensor (B70), engine speed
- LH and RH oxygen sensors upstream of catalytic converter (G3/3, G3/4)
- Altitude pressure sensor in ME-SFI [ME] control unit, atmospheric pressure for altitude adaptation
- Engaged intake manifold length
- Correction programming with the Xentry diagnostics (during acceleration)

The requirements of the torque coordination function are also taken into account.

Function sequence for injection regulation
The ME-SFI [ME] control unit controls the injection time in the following operating conditions:
^ Function sequence for partial load operation
^ Function sequence for wide open throttle operation
^ Function sequence for acceleration

Function sequence for partial load operation
In partial load operation, when the engine is warm, the ME-SFI [ME] control unit computes the actuation time of the injection valves (Y62) according to the lambda control and the requested engine torque.

Function sequence for wide open throttle operation
In wide open throttle operation, when the throttle valves are fully open, the ME-SFI control unit extends the actuation time of the injection valves in order to ensure maximum engine torque.
At the accelerator pedal sensor, about 10 to 90% slewing range is defined as partial load and more than about 90% slewing range is defined as wide open throttle.

Function sequence for acceleration
When there is rapid variation of the accelerator pedal position, the throttle valves open and close rapidly. This causes the mixture to become briefly leaner or more rich.
To prevent this, the ME-SFI [ME] control unit adapts the fuel-air mixture, by shortening or lengthening the actuation time of the injection valves according to a characteristics map.
This prevents jerking of the engine.