Fuel injector systems basically inject a specific amount of fuel in the combustion chamber of an internal combustion engine according to the requirements of the engine. Initially, carburetors were used as an input of fuel supply to the gasoline engines before the use of fuel injection systems. Fuel injector is a valve that is controlled electronically by the ECM (Engine Control Module). The injectors according to the load on the engine are able to open a number of times in the matter of few seconds.
Following are some of the types of Fuel Injector Systems used in cars:
- Carburettor.
- Throttle Body Injection (TBI).
- Multi-Point Fuel Injection (MPFI).
- Common Rail Direct Injection (CRDi)
Carburetor: Carburetors were the devices used in the older cars for mixing of air and fuel,which further was supplied to the combustion chamber. Fuel injectors further replaced carburetors due to its main advantage of control over the fuel supply according to the needs.
Throttle Body Injection: Carburetors which became obsolete were replaced by the simplest type of fuel injection system. An ECU is used which regulates the amount of fuel to be supplied. These systems have very low maintenance and are not expensive.
Multi-Point Fuel Injection: The newer cars replace Throttle body Injection with Multipoint fuel injection. The metering of air-fuel ratio is very precise and the response time is also very accurate. There are multiple injectors located for each cylinders unlike a normal centrally located injector. The engine control module takes input from the number of sensors and according to the load on the engine the fuel supply to the respective cylinder is adjusted. The appropriate supply of fuel to the cylinder have resulted in a better fuel consumption and also the emissions have been cleaner.
Common Rail Direct Injection:CRDi is a injection system which is controlled by the Electronic Control Unit. When ECU sends electronic signals, the valves of the appropriate cylinder open and fuel at a specified pressure is sprayed in the cylinder. The injection pressure is built up independently from the load and the engine speed. The start of injection and injection time are set by the Electronic distribution control unit by means of electrically actuated solenoid valves. It provides high injection pressure even at low engine speeds.
