WORKING PRINCIPLE
This system is capable of controlling the actual tested air-fuel ratio under all engine speeds to
stay close to the equivalent proportion of the chemical reaction, so as to protect the catalyst
package and subsequently reduce the discharge of pollution. The oxygen sensor analyses the
oxygen content of the discharge gas using real-time principle and makes it possible for the
ECU to control the amount of injecting fuel to correct the air-fuel ratio. The fuel with a
pressure of about 3.5 bars is directly injected into the air intake manifold near the throttle
valve.
The fuel injectors of all cylinders are utilizing a sequential phase angle control method
according to the intake sequence and the opening time of the air intake valves; the injection
destinations are stored in the ECU map, and can vary autonomously according to the engine
speeds and intake air pressures. The application of sensors in the system is a basic strategy
used to correct the engine under all operating conditions. The system is implementing an
induction type of electrical discharge ignition, where the power source module in the ECU
controls the ignition timing. The ignition advance angle is calculated according to the engine
compression ratio and intake air volume. The idling speed is maintained at stable condition
through controlling the opening of the branch-connection pipe by a step motor and also
through the changing of the ignition points.
Other than capable of obtaining the input signals and controlling the output components, the
system has also equipped with various other functions. These functions include the following:
- When self-diagnose that the sensor is faulty, adopt the restoration strategic control.
- Restoration of the self-regulating mixed concentration engine and variances in spare parts.
- Exchange data with the diagnostic tester.
The idling speed of the engine and the amount of CO in the air discharged must not be
manually adjusted.
G-4