Sensor - input signals
Transporter T4 crankshaft speed (main parameter).
The speed sensor is located above the toothed crown and transmits to the microprocessor module the pulses generated during the rotation of the crankshaft (see Fig. 302). - Crankshaft position
The crankshaft position sensor, located above the flywheel ring gear, generates impulses for the piston to pass through the TDC and transmits them to the microprocessor module.
- Pressure of incoming air (main parameter).
Using a potentiometer, the angular position of the damper in the air mass meter is determined, and the corresponding electrical signal is transmitted to the microprocessor module. Signal processing
- Determination of the injection time.
Initially, the base amount of fuel injected is determined depending on the engine load.
- Determining the ignition timing.
The ignition timing is determined on the basis of the characteristic curve and correction parameters (depending on the engine temperature) for the phases: starting, idling, deceleration phase, as well as partial and full load.
- Determining the angle of rotation of the crankshaft (piston position near TDC).
The angle depends on the speed and voltage of the battery.
Rice. 307 Throttle assembly device - typical design
Output signals
- Determination of injection parameters.
The microprocessor in the microprocessor module calculates the injection time based on the engine operating conditions and determines the end of the injection by giving an appropriate signal. - Determination of ignition parameters.
The microprocessor in the microprocessor module calculates the ignition timing based on input parameters such as engine speed, engine load, and some others. The angle of the closed state is also determined. Both values set the spark plug duration, which is the duration of the closed state phase. The ignition pulse controls the flow of current through the coil winding during the final ignition phase. Injectors
The design and principle of operation of fuel injectors is completely similar to that described for the Digifant .
Volkswagen air flow meter device .