Ford Motorcraft EFI DOHC Engine Injection System Components
1 - Intake manifold, 2 - Throttle body, 3 - Idle air control valve air supply line, 4 - Coolant temperature sensor, 5 - Intake air temperature sensor, 6 - Fuel pressure regulator, 7 - Fuel temperature sensor, 8 - Injector manifold, 9 - Injector gaskets, 10 - Fuel injectors, 11 - Idle air control valve, 12 - Air vibration damper, 13 - Air filter cover, 14 - Replaceable air filter element, 15 - Air filter housing.
Design and principle of operation
In the Ford Motorcraft EFI electronic multi-point fuel injection system, fuel is supplied at a constant low pressure to four injectors, which spray it onto the intake valves. The amount of fuel sprayed is controlled by the injector opening time, determined by the EEC IV electronic control unit based on engine speed and flow rate. air consumed by the engine.
An electric fuel pump, immersed in the tank, constantly forces fuel through the pipes to the fuel filter, pressure regulator (6), injector manifold (8) and injectors (10). The pressure regulator maintains a constant pressure for a given vacuum in the intake manifold.
The amount of fuel supplied to each cylinder is regulated by the injector opening time during each cylinder operating cycle.
The electronic control unit EEC IV determines this time on the basis of the following signals:
- sensor (5) of incoming air temperature;
- engine speed sensor located in the ignition distributor;
- coolant sensor (4);
- throttle position sensor located in the throttle housing (2);
- automatic transmission gearshift lever position sensor (in vehicles with automatic transmission);
- air conditioning compressor switch sensor (in cars with air conditioning).
Based on these signals, the electronic control unit EEC IV ensures that the fuel and air mixture composition is optimal for the given engine operating conditions.
In addition, it controls the idle speed control valve (11), which adjusts the idle speed by supplying additional air through the pipeline (3). During engine starting, the idle speed control valve is open to the maximum.
During idle, its opening varies depending on need, maintaining a constant engine speed.