Starting Mode (Port and TBI Injection)

When the ignition switch is rotated to the "On" position, the ECM energizes the fuel pump for two seconds and fuel pressure is built up to the TBI unit. The ECM then checks the coolant temperature sensor, the TPS and determines the proper air/fuel mixture for starting.

The ECM controls the air/fuel ratio by changing the length of time the injectors are turned on and off. This is accomplished by "Pulsing" the injectors for short periods of time.