The so-called electronic fuel injection is to measure the amount of air sucked into the engine, and then supply an appropriate amount of gasoline to the engine by high-pressure injection. The computer control process of controlling the mixture ratio of air and gasoline is called electronically controlled fuel injection. This oil supply method is different from the traditional carburetor in principle. The carburetor relies on the negative pressure generated by the air flowing through the carburetor waiting tube to suck the gasoline in the float chamber into the throat and form a combustible mixture with the air flow mist.

Control contents and functions of electronic fuel injection system (FE1):
1. The fuel injection quantity control ECU takes the engine speed and load signal as the main control signal to determine the basic fuel injection quantity (the opening time of the fuel injection solenoid valve), and correct it according to other relevant input signals, and finally determine the total fuel injection quantity.
2. The injection timing control ECU controls the injection time at an optimal time according to the signal of the crankshaft phase sensor and the firing sequence of the two cylinders.
3. When decelerating and limiting fuel cut-off control motorcycle driving, when the driver quickly releases the throttle, the ECU will cut off the fuel injection control circuit and stop fuel injection to reduce exhaust emissions and fuel consumption during deceleration. When the engine accelerates and the engine speed exceeds the safe speed, the ECU will cut off the fuel injection control circuit at the critical speed and stop fuel injection to prevent the engine from over speed and damaging the engine.
4. Fuel pump control When the ignition switch is turned on, the ECU will control the fuel pump to work for 2-3 seconds to establish the necessary oil pressure. At this time, if the engine cannot be started, the ECU will cut off the control circuit of the fuel pump and the fuel pump will stop working. The ECU controls the gasoline pump to maintain normal operation during engine starting and running.

Airway injection mode. The typical features of this method are that the original engine is smaller, the manufacturing cost is lower, and the working energy efficiency is greatly improved compared with the ordinary carburetor engine.

The electronically controlled fuel injection system has the following advantages compared with the carburetor type of supply and mixing mode:

1. The adoption of electronic control technology reduces exhaust pollution and fuel consumption of the engine, which can meet the requirements of stricter emission regulations;
2. The electronic control unit (ECU) responds quickly to the change of the throttle valve, which improves the handling performance and acceleration performance of the engine, and can maintain good dynamic performance indicators; Allowing the engine to adopt higher compression ratio improves the thermal efficiency of the engine and reduces the knock tendency of the engine;
3. EFI system has strong adaptability. For engines of different models, only the “pulse spectrum” in the ECU chip needs to be changed, while the same oil pump, nozzle, ECU, etc. can be used in many products of different specifications and models, which is convenient to form a series of products;
4. Convenient engine performance adjustment.

The difference between the two is that the carburetor throttle response is poor, the fuel supply control is poor, the fuel consumption is high, the fuel atomization effect is poor, the cold start is poor, the structure is complex, and the weight is large. The automobile carburetor engine has long been out of production. The electronic fuel injector has accurate fuel supply control, rapid response, good fuel atomization effect, complex structure, small volume, light weight, fuel consumption rate much less than the carburetor, and good cold start effect.