Modes of Operation

ENGINE STARTING ENRICHMENT
In order to improve starting performance, enriching compensation at start is carried out. For a certain time after the engine is started, air/fuel mixture is slightly enriched to stabilize the engine speed. The amount of compensation varies depending on the Engine Coolant Temperature (ECT) sensor input.

ENGINE WARM-UP ENRICHMENT
When the engine is cold, additional fuel is added to ensure good driveability until the Engine Coolant Temperature (ECT) sensor reaches the specified level. The amount of air/fuel mixture is decreased as the ECT sensor rises.

ACCELERATION ENRICHMENT
During acceleration the fuel injector's pulse is lengthened to add more fuel. This ensures a smooth stable acceleration of the engine. The additional fuel is added based on the Engine Coolant Temperature (ECT) sensor and manifold pressure.

POWER ENRICHMENT
To provide maximum power during high engine load driving conditions, the air/fuel mixture is made richer. This is based on the Manifold Absolute Pressure (MAP) sensor input, Engine Coolant Temperature (ECT) sensor input and Throttle Position (TP) sensor input.

DECELERATION ENRICHMENT
To obtain a proper air/fuel mixture ratio during deceleration, leaning compensation is carried out when the intake manifold pressure indicates that the engine has little or no load condition.

SYSTEM VOLTAGE COMPENSATION
A power voltage drop delays the mechanical operation of the fuel injector. The actual injection time becomes shorter for the time that electricity is supplied to the fuel injector. To compensate for this, the fuel injector pulse is lengthened.

BASE AIR/FUEL RATIO COMPENSATION
The air/fuel ratio may vary due to such factors as variation in each engine itself and aging.

To compensate such variation, feedback compensation is used and base air/fuel mixture ratio is adjusted to a proper level to maintain optimum air/fuel ratio.

FUEL CUTOFF
Fuel injection stops (with operation of the fuel injector prevented) when decelerating (i.e., when the throttle valve is at idle position and the engine speed is high), so that unburned gas will not be exhausted and injection starts again when above conditions are not met.

The fuel injection also stops when the engine speed exceeds 7,000 RPM to prevent overrun which affects the engine adversely, and it starts again when the engine speed reduces to less than 6,800 RPM. In order to improve starting performance, enriching compensation at start is carried out. For a certain time after the engine is started, air/fuel mixture is slightly enriched to stabilize the engine speed. The amount of compensation varies depending on the Engine Coolant Temperature (ECT) sensor