Fuel Injector: Description and Operation

Fuel Injectors
There are two types of injector, one for normally aspirated engines and one for turbocharged engines. The injectors for turbocharged engines have higher flow capacity and lower electrical resistance.

The injectors are of solenoid type with needles and seats. They open when current flows through them and close by means of a powerful spring when the current is turned off.

To obtain optimal combustion and consequently cleaner exhaust emissions, the injectors are provided with 4 holes to ensure good distribution of the fuel.

The fuel jets are set with a high degree of accuracy (two jets for each inlet valve). This calls for extreme precision in the mounting of the injectors and to ensure their exact positioning they are fixed in pairs in special mounting brackets between cylinders 1, 2 and cylinders 3, 4

The injectors are supplied with current from the main relay and the control module grounds them as follows:

- Injector 1 is connected to ground via pin 3
- Injector 2 is connected to ground via pin 4
- Injector 3 is connected to ground via pin 5
- Injector 4 is connected to ground via pin 6