Starting Mode

NOTE: There are several operating parameters that PCM looks at to determine how much fuel to give engine. Based upon voltage signals from several sensors, fuel is delivered to engine under one of several operating "modes." All modes are controlled by PCM and are described below.

When key is first turned "ON", PCM will turn on fuel pump relay for two seconds. The fuel pump energizes, building up fuel pressure to fuel rail. The PCM then checks coolant temperature sensor, throttle position sensor, and crank signal, and determines proper air/fuel ratio for starting. This ranges from 1.5:1 at -36°C to 12.0:1 at 94°C.

The PCM controls amount of fuel delivered in STARTING mode by changing how long injectors are turned on. This is done by "pulsing" injectors for very short times.