Operation of the gasoline injection system (Scorpio 2)

An electric fuel pump takes fuel from the fuel tank and delivers it through a filter located at the bottom of the body to the injection unit. The pressure regulator maintains constant fuel pressure in the system (depending on the engine, the excess pressure is 2.7-3.0 bar).

Valve injectors are electromagnetically controlled and inject fuel intermittently, i.e. in portions, into the intake manifold directly in front of the intake valves. The engine control unit regulates the duration of injection and thus the amount of fuel injected.

The air required for combustion is sucked in by the engine through the air filter and passes through the throttle valve assembly and the intake manifold to the intake valves. The amount of air sucked in is regulated by the throttle valve, which the driver controls via the accelerator pedal and the gas rod. The amount of air sucked in is determined by the air flow meter. The air flow meter housing contains a pressure flap, which is deflected to a certain position by the pressure of the incoming air and is held in this position. The angular position of the flap is a measure of the amount of incoming air. The corresponding signals are transmitted to the control unit via a potentiometer.

The engine control unit is a small, very fast computer. It calculates the optimal ignition timing, injection start time and the amount of fuel injected. Signals from various sensitive elements and sensors allow the correct dosing of the amount of fuel injected in any driving situation.

If important sensors fail, the control unit switches to a backup program. This avoids engine damage and allows the journey to continue. In this case, the engine runs unevenly and tends to stall when the gas pedal is pressed.