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Fuel injection

Fuel injection


Fuel injection in the Saab Trionic is sequential, which means that fuel injection follows the engine's firing order.The fuel injection time is calculated by the control module chiefly on the basis of the following information:


• pressure in the intake manifold

• intake air temperature

• engine speed

• engine coolant temperature

• oxygen content of the exhaust gases

• any knocking

• throttle position


Pre-injection


When the ignition switch is turned to the Drive position, the system and fuel pump relays operate. At the same time, all the injectors open to inject a small amount of fuel onto the intake valves. The open time is determined by the engine coolant temperature. The aim is to achieve a shorter starting time.