Methods of fuel injection:
1. Sequential fuel injection. (SFI)
2. Grouped fuel injection.
3. Simultaneous fuel injection.
4. Continuous injection.
1. Simultaneous Injection: Injection of fuel occurs at the same time for all cylinders every revolution of the crankshaft. Therefore, fuel is injected twice within each fourstroke cycle. The injection timing is fixed with respect to crank/ cam shaft position.
2. Group Injection: The injectors are divided into two groups that are controlled separately. Each group injects once per four-stroke cycle. The offset between the groups is one crankshaft revolution. This arrangement allows.
3. Sequential Injection: Each injector is controlled separately. Injection timing, both with reference to crank/ camshaft position and pulse width, can be optimized for each individual cylinder.
4. Continuous injection:-This system usually has a rotary pump. The pump maintains a fuel line gauge pressure of about 0.75 to 1.5 bars. The system injects the fuel through a nozzle located in manifold immediately downstream of the throttle plate. In supercharged engine, fuel is injected at the entrance of the supercharger. The timing and duration of the fuel injection is determined by ECU depending upon load and speed.