Modes of Operation

ENGINE STARTING ENRICHMENT
In order to improve starting performance, fuel enrichment during start up is carried out. For a certain time after the engine is started, the air/fuel mixture is enriched slightly in order to stabilize the engine speed. The amount of compensation varies depending on the engine coolant temperature as measured by the Engine Coolant Temperature (ECT) sensor.

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

ACCELERATION ENRICHMENT
During acceleration, the pulse of the fuel injector is lengthened in order to deliver more fuel. The additional fuel required is relative to the engine coolant temperature. Acceleration Enrichment ensures smooth and dependable engine acceleration.

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

DECELERATION ENRICHMENT
In order to obtain the desired air/fuel mixture ratio during deceleration, the PCM will almost eliminate fuel delivery when the Manifold Absolute Pressure (MAP) sensor indicates that the engine has a little or a 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. In order to compensate for this the fuel injector pulse is lengthened.

BASE AIR/FUEL RATIO COMPENSATION
The base air/fuel ratio may vary due to differences in individual engines and mileage. In order to compensate for such variations, feedback information is used to adjust the base air/fuel mixture in order to maintain the optimum air/fuel ratio.

FUEL CUTOFF
Fuel injection stops (the operation of the fuel injector is inhibited) 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. Fuel injection starts again when the above conditions are no longer present.

Fuel delivery also stops when the engine speed exceeds 7,000 RPM. This will prevent engine overrun which adversely affects the engine. Fuel delivery starts again when the engine speed decreases to less than 6,800 RPM.