Chapter 124 Comprehensive system review, the birth process of the maintenance manual
“The electronic injection system provides fuel through the fuel supply device and mixes the clean air provided by the air supply device into flammable gas, which enters the cylinder. Then it is ignited by the ignition system, and finally the exhaust gas is discharged. The entire process is completed under the monitoring and coordination of the ECU. "
"These four-part structure is also the most important part of the electronically controlled fuel injection engine, and any part of it is. Any failure may lead to flameout. "
" Let's start with these four parts of the structure and analyze the flameout caused by the fault. "
Chen Chenxing. He quickly took off his gloves and quickly took out his notebook and pen, preparing to record what Jiang Hui said.
When he was about to strike, he had no way of recording it, so he could only keep it in his mind.
It’s different now. A good memory is not as good as a bad writing. He understands this truth.
“The first reason for engine stalling is that there is a problem with the fuel supply device, usually the oil line is clogged.”
“When the engine is working normally, it first needs the fuel supply system. The oil pump draws the fuel from the fuel tank, enters the fuel distribution pipeline through the fuel filter, and then sprays it out from the fuel injector to form a mixture of oil and gas. "
"We can sort out the fuel when the engine is working. Flow direction, it passes through the electric fuel pump, fuel filter, enters the fuel pipe, and is finally ejected from the fuel injector. ”
"In this process, the fuel pump and the fuel injector are the most prone to failure."
"The function of the electric fuel pump is to pump the fuel in the tank into the fuel supply pipe to inject fuel to each The system provides the required fuel. "
"Normally, it is immersed in gasoline to work and relies on gasoline to cool down. Its common fault is blockage caused by impurities in the gasoline, and also due to gasoline. Insufficient results lead to high temperature and burnout.”
Jiang Hui said it very seriously, and Chen Chenxing recorded it very carefully.
“The gasoline nozzle used in EFI engines is electromagnetic. Under the action of the magnetic field of the electromagnetic coil, pressurized gasoline is sprayed out from the fuel injection port.”
"Common faults include stickiness, blockage, and leakage of the fuel injector, as well as short-circuit, open-circuit, and malfunction caused by aging of the electromagnetic coil."
"Our domestic oil products are not very good, so this problem can be considered We often encounter it, and of course we have to pay attention to whether the gasoline filter is still working properly.”
A question that sounds boring, Chen Chenxing understood it immediately after Jiang Hui sorted out the system.
This made him feel even more powerful about his master.
During this period, he had learned about how other car repairmen learned car repair skills. They had to study with their master for several years before they could barely get out of the car repair business.
The key is that the skills of those people are definitely far inferior to their master.
“The second problem when the engine stalls is that the air supply device fails.”
“The air supply device is equally important as the oil supply device. Its smooth flow also ensures that the ratio of the oil-air mixture is normal. The key is that in this system, the air passes through the air filter, air flow meter, throttle body intake manifold, and intake manifold, and finally enters the cylinder. "
"The air supply device is throttled. The valve is undoubtedly the most important component, and it is also the component most prone to problems. When you encounter a similar flameout problem in the future, the first thing you should check is the throttle valve located at the intake throat. ”
< br>“The function of the throttle is to control the amount of combustible mixture entering the cylinder by adjusting the opening. The metaphor is the throat of the engine.”
"Since the air flow is largest in the gap where the throttle valve is opened, the space is small, and the gas temperature is low, this part is most likely to condense impurities, so it needs to be cleaned according to a certain period."
"If the throttle valve is due to impurities Causes blockage, which will lead to insufficient air intake, causing stalling and unstable idling. ”
“In addition, leakage in the intake manifold can also cause unstable idling or even stalling. When such a failure occurs, the vehicle will fail. There will be strong shaking..."
While explaining to Chen Chenxing, Jiang Hui suddenly realized that if he compiled these common knowledge about car maintenance, it seemed that it could become a classic book of this era?
Especially for people in the automotive industry, it is definitely a treasure book.
However, my time is limited, so I can consider asking Chen Chenxing to assist in this matter.
Thinking of this, Jiang Hui was more willing to systematically explain to Chen Chenxing the principles and solutions to various car failures.
“The third problem of engine stalling is the failure of the ignition system. The Cadillac failure we repaired at the U.S. Liaison Office in Beijing last time was this type of failure.”
“When the oil-air mixture enters the cylinder normally and still misfires, it is very likely that the ignition system is faulty.”
“The function of the ignition system is to periodically activate the gas in accordance with the working sequence of the cylinder. An electric spark of sufficient energy is generated between the two electrodes of the spark plug. ”
"Of course, the most important part of this is the spark plug. Because it works in a cylinder with high temperature and high pressure, the spark plug is also the most prone to failure in the ignition system."
"Common spark plug failures include leakage. Abnormal flashover and electrode burnout, etc. ”
“Normally, when flameout is caused by a spark plug, it is best to completely solve it by replacing the spark plug. When it is inconvenient to replace it, it can also be solved. Emergency measures include cleaning the electrodes and adjusting the length of the central electrode. "
"In addition to spark plug failure, damage to the generator, virtual connection or short circuit of the line, and battery leakage will also cause the problem. Poor ignition caused by no power will eventually lead to flameout. "
"When this happens, you can sound the horn to determine whether there is power and check whether the belt is too loose or broken. "
Jiang Hui's explanation speed was not too slow. Fortunately, Chen Chenxing's hand speed was very fast. In addition, recording these contents was not like a translation manuscript, so the writing should be clearer.
It doesn’t matter if it’s a bit sloppy now, as long as he can understand it himself.
One is willing to teach and the other is willing to learn, so the efficiency is naturally high. "The fourth common type of engine stalling is the failure of the electronic control system."
"In most cases, various sensor failures lead to the ECU's protective fuel cutoff. What we encountered today It’s this type of fault.”
"In EFI engines, electronic systems play an increasingly important role. The electronic control system is composed of sensors, electronic control units and actuators. The core component is the electronic control unit."
"Just now I have introduced the main types of sensors and their functions. These sensors feed back signals to the ECU, which then issues work instructions to the central injector and other actuators. "
"The ECU is increasingly burdened. When it is responsible for monitoring the status of the vehicle, it also brings some problems. "
"When a certain sensor fails, the ECU will not be able to correctly judge the current situation, and then take measures such as stopping fuel injection. Protective measures may lead to flameout. "
"In terms of sensors, the most important ones are the air flow sensor, throttle position sensor, and oxygen sensor. br>
Although the sensor situation was well introduced during the car repair process, the specific fault problem was not explained enough.
Jiang Hui is now thinking about asking Chen Chenxing to help compile a book of the type "Car Maintenance Guide" in the future, so naturally he needs to organize the materials well.
Invisibly, Chen Chenxing has witnessed the birth of a generation of car maintenance manuals.
In the future, this story can be well publicized and become a classic in magazines such as "Reader" or "Yilin".
“For example, if there is something wrong with the air flow meter, then the ECU does not sense or incorrectly senses the current air flow, which will cause the ECU to be unable to correctly estimate the current air condition.”
< br>
"To protect the engine, the ECU will stop the fuel supply system to inject fuel into the engine. This is not difficult to explain why the engine stalls when the air flow meter does not work properly."
"Similar to this There are also oxygen sensors and the throttle position sensor we encountered today, which also caused the ECU to stop supplying fuel or supplying fuel abnormally, causing flameout and other phenomena. "
Jiang Hui was a bit exaggerated. When his tongue was dry, Kato Hiroyuki appeared again.
"Jiang Sang, how is the maintenance going?"
Jiang Hui looked at his watch and had an idea.
"The gearbox fault has been solved, and the engine is being repaired now. Just give us some more time."
Hearing what Jiang Hui said, Kato Hiroyuki breathed a sigh of relief, but he was also curious, "The transmission What's wrong with the tank?"
"The main problem is that the oil pump is clogged, and there are problems with some other oil supply lines."
At this time, there is no specific problem to tell Kato Hiroyuki. relationship, when he explains the situation to the country for confirmation in the future, he will also find that what Jiang Hui said makes sense.
Maybe next time I will be willing to take the initiative to ask Jiang Hui to come over for repairs.
"By the way, does your car often drive at low speed?"
It's time to eat, so there is obviously no harm in improving Kato Hiroyuki's favorability towards him.
"It is true. You are also very aware of the traffic situation in the capital area."
"There are bicycles all over the streets. Our drivers have never been very used to it. In most cases, they only dare to "Driving at a low speed."
Kato Hiroyuki didn't know why Jiang Hui asked, but he answered anyway.
"It is still necessary to increase the speed from time to time to avoid driving at low speed for a long time, because driving at low speed for a long time will cause the transmission oil pump to fail to work properly and affect the life of the transmission."
Jiang Hui explained, Kato Hiroyuki I understand.
"I understand, thank you for reminding me, I will tell the driver about it when the time comes."
"Is there anything else I should pay attention to?"
Kato Hiroyuki now said to Jiang Hui's favorability level improved slightly and he simply asked more questions.
"It's best to change your gearbox oil in the near future. However, this kind of gearbox oil must be specially produced and is probably not available in China."
"I will arrange this later and let people leave." I brought a bottle from China for the first time.”
Kato Hiroyuki is also a person who can drive, so he knows that Jiang Hui’s advice is meaningful.
"There is nothing else for now. After the engine failure is repaired this afternoon, I will tell you more in detail."
A simple reminder, Jiang Hui thinks is enough Well, there is no need to talk too much to Kato Hiroyuki.
"Okay, let's go eat first!"
Today's ten thousand words have been completed, veterans, please support me with your monthly vote
(End of chapter)