Fuel Control: Notes

ECU calculates base injection pulse width by processing signals from various engine sensors. On 240, 940 and 960, information from crankshaft position sensor (RPM) is used to trigger timing of fuel injection. On 850, engine speed is provided to fuel injection ECU via ignition ECU. On all models, during normal driving conditions, injection duration is regulated in reference to mass air meter/sensor, engine speed, oxygen content of exhaust gases and coolant temperature. Under full throttle conditions, a richer fuel mixture is provided for increased power and to reduce combustion heat in engine and catalytic converter.