I think it is better to sort out an article by repeating it frequently. There are some reasons why the car can't catch fire, such as timing system, circuit system and fuel supply system. Today, let's learn more about the fuel supply system.
Then some friends have to ask again, why must the fuel supply system not talk about others?
If the car is compared to an adult, the engine is the heart, the fuel is the blood, the blood transmits nutrition to the human body, and the fuel is the energy supply source for the start and running of the car.
If there is a problem with the fuel supply system, 100% of it cannot catch fire. Without energy, where is the power? Anyone who doesn't eat for a week can only lie in bed and can't go out for waves, right?
Next, let's talk about some dry goods!
1. Composition of fuel supply system
It is composed of electric fuel pump, filter, oil pressure regulator, pulse damper, oil pipe and fuel injection nozzle.
2. Electric fuel pump classification by structure
Turbo-type, roller type, rotor type and blade type. According to the installation position, it can be divided into built-in type and external type. Generally, the built-in type is the most. The structure of Vane fuel pump is as follows:
3. Fuel filter
The fuel filter is installed in the high-pressure oil circuit behind the fuel pump, mainly filtering impurities and moisture of the fuel type. Generally, 20000-40000KM or 1-2 years should be replaced.
Be sure to change it on time. If you don't change it for too long, it will affect the car!
4. Oil pressure regulator
The main function is to adjust the fuel pressure to keep the fuel injection pressure difference constant.
5. Pulse damper
The main function is to reduce the fuel pressure fluctuation caused by fuel injector injection, so as to keep the fuel system pressure stable.
6. Tubing
Provide the flow of fuel and keep the pipeline under a certain pressure after flameout to facilitate the next start.
7. Nozzle
Receiving the signal from the computer will provide the engine with appropriate energy.
1) According to the injection port: Shaft needle type, hole type
2) according to the resistance value: high resistance (13~16 Ohm), low resistance (2~3 Ohm)
8. About breakdown in fuel system maintenance methods
This is the key point. Hurry up and take notes.
1) the general troubleshooting method of oil circuit is to use oil pressure gauge to detect the oil circuit pressure. The normal pressure value is 0.25~0.35MPa. If the pressure value is too much lower than the theoretical value, the oil pump pressure is not enough and the pressure is too high, check whether the return pipeline is blocked. If the return pipeline is normal, the fuel pressure regulator is faulty and should be replaced.
2) Check the nozzle can be checked by measuring resistance with multimeter. The high resistance value is between 13 and 16 ohm, and the low resistance value is between 2 and 3 Ohm. You can also use an oscilloscope to look at the working waveform.
3) the positive electrode of the nozzle is the vehicle voltage controlled by fuse box, which is usually 12v. The negative electrode is the pulse width signal provided by the engine computer after receiving various sensor signals after calculation.
