Note: In the Z22YH engine, injection is carried out directly into the combustion chamber.
The engine control module, observing the ignition sequence, regulates the opening time of the injector channels and thereby the amount of injected fuel. In addition, the ECM controls the throttle valve by adjusting the amount of air supplied. Initially, to determine the amount of fuel supplied to the engine cylinders, only the incoming air flow was measured. But gradually, new dependencies were identified that affect the efficiency of fuel combustion, and the requirements for exhaust gas toxicity were tightened, which led to. followed by the complication of engine control systems. Modern fuel injection control systems are. a complex set of sensors, control units, actuators and electronic circuits (see illustration 12.1). Below is a description of the principles of operation of some of them:
- The gas pedal position sensor is built into the pedal assembly. From sensor to engine control module (ECM) an appropriate electrical signal arrives, setting the values of the required mode of vehicle movement;
- The throttle control module contains the actuator (stepper motor) and damper potentiometer. The electric motor regulates the position of the throttle valve and allows you to maintain a constant idle speed, regardless of the connection of additional consumers. through the potentiometer, the ECM receives information about the current value of the throttle angle;
- The camshaft position sensor provides the ECM with information about the ignition timing in the first cylinder of the engine to synchronize the ignition timing and injection sequence in other cylinders;
- A thin sensor plate is installed in the body of the air mass measurement sensor, through which an electric current is passed. Due to the passing air flow, the plate is cooled. The control unit regulates the heating current so that the temperature of the plate remains constant. Current fluctuations during heating allow the ECM to determine the condition of the engine load and, accordingly, regulate the amount of fuel injected;
- The coolant temperature sensor is installed in the thermostat housing. It is an NTC resistor - as the temperature of the coolant rises, its resistance decreases and the corresponding signal is sent to the ECM;
- The knock sensor is mounted under the exhaust manifold in the cylinder block. It sets the ignition moment at the border of the start of detonation combustion of the fuel, thereby, on the one hand, preventing the process of detonation combustion of the fuel mixture, and on the other hand, ensuring the most complete combustion of the fuel and reducing its consumption.
Different systems may differ from each other in the number of elements involved, depending on the design of the power unit and the requirements for a particular engine. Independent intervention in the adjustment and configuration of these systems is not allowed. For this, special diagnostic and adjustment devices are used, which are available, as a rule, only at specialized service stations.
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