Starting Mode

PURPOSE
The cold start circuit is important when engine coolant temperature is very low because the other injectors will not be pulsed "ON" long enough to provide the needed amount of fuel to start the engine.

OPERATION
When the ignition is switched On, the Electronic Control Module (ECM) energizes the fuel pump for two seconds and pressure is built up in the fuel rail. The ECM then checks the Coolant Temperature Sensor (CTS), the Throttle Position Sensor (TPS) and crank signal and determines the proper air/fuel ratio for starting. The ECM controls the air/fuel ratio by changing how long the injectors are turned "ON" and "OFF". This is accomplished by "Pulsing" the injectors for very short periods of time.