The car giant started by marrying the daughter of the king

Chapter 124 Comprehensive and systematic review, the birth process of the maintenance manual

"The electronic fuel injection system mixes the fuel provided by the fuel supply device with the clean air provided by the air supply device into a combustible gas, which is then ignited by the ignition system after entering the cylinder and finally discharged. The entire process is completed under the monitoring and coordination of the ECU."

"These four parts are also the most important parts of the electronic fuel injection engine. Failure of any one of them may cause the engine to stall."

"Let's start with these four parts and analyze the flameouts caused by faults."

Chen Chenxing quickly took off his gloves, took out his notebook and pen, and prepared to write down what Jiang Hui said.

Just now when he was about to start working, he had no way to record it and could only try hard to remember it in his mind.

It’s different now. A good memory is not as good as a bad pen. He understands this principle.

"The number one reason an engine stalls is a problem with the fuel supply, usually a clogged fuel line."

"When the engine is working normally, the fuel pump in the fuel supply system first needs to pump the fuel from the fuel tank, enter the fuel distribution pipeline through the fuel filter, and then be sprayed out by the fuel injector to form an oil-gas mixture."

"We can specifically sort out the direction of fuel flow when the engine is working. It passes through the electric fuel pump, the fuel filter, enters the fuel pipe, and is finally sprayed out by the injector."

"The fuel pump and the fuel injectors are the most vulnerable areas to failure during this process."

"The function of the electric fuel pump is to pump the fuel in the fuel tank into the fuel supply pipe to provide the required fuel to each injection system."

"Normally it will work while immersed in gasoline and rely on gasoline to keep it cool. Common failures are blockages caused by impurities in the gasoline and burnouts caused by high temperatures due to insufficient gasoline."

Jiang Hui spoke very seriously and Chen Chenxing recorded it very carefully.

"The gasoline nozzle used in the electronic fuel injection engine is electromagnetic, and the pressurized gasoline is sprayed out from the injection port under the action of the magnetic field of the electromagnetic coil."

"Its common faults include sticking, clogging, leakage of the fuel injector, and failure caused by short circuit, open circuit and aging of the electromagnetic coil."

"The quality of our domestic oil is not very good, and this problem is often encountered. Of course, we also need to pay attention to whether the gasoline filter is still working properly."

It was a question that sounded very boring, but after Jiang Hui's systematic analysis, Chen Chenxing immediately understood it.

This made him feel even more deeply how powerful his master was.

During this period of time, he also learned how other mechanics learned their car repair skills. They all had to follow a master and learn for several years before they could barely become a master.

The key point is that those people's skills are definitely far inferior to those of my master.

"The second problem with the engine stalling is a malfunction in the air supply."

"The air supply device is as important as the oil supply device. Its smooth flow is also the key to ensuring the normal ratio of oil-gas mixture. In this system, the air passes through the air filter, air flow meter, throttle body intake manifold, intake manifold, and finally enters the cylinder."

"The throttle valve is undoubtedly the most important component in the air supply device, and it is also the component that is most prone to problems. In the future, if you encounter similar flameout problems, the first thing you should check is the throttle valve located at the intake throat."

"The function of the throttle is to control the amount of combustible mixture entering the cylinder by adjusting the size of the opening. It can be likened to the throat of the engine."

"Since the gap where the throttle is opened has the largest air flow, 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 clogged by impurities, it will cause insufficient air intake, resulting in flameout and unstable idle speed."

"In addition, a leak in the intake manifold can also cause unstable idling or even flameout. When such a fault occurs, the vehicle will vibrate violently..."

While explaining to Chen Chenxing, Jiang Hui suddenly realized that if he compiled this common knowledge about car maintenance, it would probably become a classic book of this era?
Especially for people in the automotive industry, it is definitely a treasure.

However, my time is limited, so I can consider asking Chen Chenxing to assist me in this matter when the time comes.

Thinking of this, Jiang Hui was more willing to systematically explain to Chen Chenxing the principles and solutions of various automobile failures.

"The third problem with engine stalling is a malfunction in the ignition system. The last time we repaired a Cadillac at the U.S. Liaison Office in Beijing, it was a malfunction of this type."

"When the fuel-gas mixture enters the cylinder normally but still misfires, it is very likely that there is a fault in the ignition system."

"The function of the ignition system is to generate an electric spark of sufficient energy between the two electrodes of the spark plug in a timely manner according to the working order of the cylinders."

"Of course, the core part is the spark plug. Since it works in the high temperature and high pressure cylinder, the spark plug is also the most prone to failure in the ignition system."

"Common spark plug failures include leakage, abnormal sparking, and electrode burnout."

"Generally speaking, in the case of flameout caused by spark plugs, it is best to completely solve the problem by replacing the spark plugs. When replacement is inconvenient, it can also be temporarily solved by emergency measures such as cleaning the electrodes and adjusting the length of the central electrode."

"In addition to spark plug failure, generator damage, line disconnection or short circuit, and battery leakage will also lead to poor ignition due to lack of electricity, and eventually cause flameout."

"When this happens, you can honk the horn to determine if there is power and check if the belt is loose or broken."

Jiang Hui's explanation speed was not slow. Fortunately, Chen Chenxing's hand speed was very fast. In addition, recording these contents was not like a translation manuscript, so the words had to be written clearly.

It doesn’t matter if it’s written a little sloppily now, as long as he can understand it.

One is willing to teach, the other is willing to learn, the efficiency is naturally very good. "The fourth common type of engine stall is electronic control system failure."

"In most cases, it is various sensor failures that cause the ECU to cut off the fuel supply for protection. The failure we encountered today is of this type."

"In electronic fuel injection engines, electronic systems play an increasingly important role. The electronic control system is composed of sensors, electronic control units and actuators, with the core component being the electronic control unit."

"I have just introduced the main types of sensors and their functions. These sensors feed back signals to the ECU, which then issues work instructions to actuators such as the central injector."

"As ECUs increasingly take on the responsibility of monitoring vehicle status, this also brings some problems."

"When a sensor fails, the ECU will not be able to correctly judge the current situation, and will take protective measures such as stopping fuel injection, resulting in flameout."

"In terms of sensors, the most important ones that are most likely to cause flameout when a failure occurs are the air flow sensor, throttle position sensor, and oxygen sensor."

Although the situation of the sensor has been well introduced during the car repair process just now, the explanation of the specific fault problem is still not enough.

Jiang Hui is now thinking about asking Chen Chenxing to help write a book of the "Auto Repair Handbook" type in the future, so naturally he has to organize the materials well.

Invisibly, Chen Chenxing also witnessed the birth of a generation of automobile maintenance handbook.

In the future, this story can be promoted well and become a classic in magazines such as "Reader" or "Yilin".

"For example, if there is a problem with the air flow meter, the ECU will not sense or sense the current air flow incorrectly, which will cause the ECU to be unable to correctly estimate the current intake conditions."

"For engine protection, the ECU will stop the fuel supply system from injecting fuel into the engine. This explains why the engine stalls when the air flow meter does not work properly."

"Similar to this are the oxygen sensor and the throttle position sensor we encountered today. They also cause the ECU to stop supplying fuel or supply fuel abnormally due to a fault, causing flameout and other phenomena."

Just when Jiang Hui was feeling a little dry-mouthed, Kato Hiroyuki appeared again.

"Jiang Sang, how's the repair going?"

Jiang Hui looked at his watch and knew what was going on.

"The gearbox problem has been fixed and the engine is being repaired now. Just give us some time."

Hearing Jiang Hui's words, Kato Hiroyuki breathed a sigh of relief, but he was also very curious, "What's wrong with the gearbox?"

"It was mainly because the oil pump was clogged, and some other oil supply lines had problems."

At this time, it doesn't matter if you tell Kato Hiroyuki the specific problems. When he reports the situation to the country for confirmation in the future, he will find that what Jiang Hui said makes sense.

Maybe next time he will be willing to take the initiative to ask Jiang Hui to come and repair it.

"By the way, does your car often drive at low speeds?"

It's time to eat soon, so there's obviously no harm in improving Kato Hiroyuki's favorability towards me.

"Indeed, you are well aware of the traffic conditions in the capital area."

"The streets are full of bicycles, and our drivers are not used to them. In most cases, they only dare to drive at a low speed."

Kato Hiroyuki didn't know why Jiang Hui asked this, but he answered anyway.

"You still have to slow down from time to time to avoid driving at low speeds for long periods of time, because driving at low speeds for long periods of time will cause the transmission oil pump to not work properly and affect the life of the transmission."

After Jiang Hui's explanation, Kato Hiroyuki finally understood.

"I see. Thanks for the reminder. I'll let the driver know when the time comes."

"Is there anything else I should be aware of?"

Kato Hiroyuki's favorability towards Jiang Hui has increased slightly, so he simply asked a few more questions.

"It would be best if you could change your transmission oil in the near future. However, this kind of transmission oil must be specially produced and you probably can't buy it in China."

"I'll arrange this later and ask someone to bring a bottle over from China next time."

Kato Hiroyuki is also a good driver, and he knows that Jiang Hui's advice is meaningful.

"There's nothing else for now. I'll tell you more about it after I fix the engine failure this afternoon."

Jiang Hui felt that this simple reminder was enough and there was no need to say too much to Kato Hiroyuki.

"Okay, let's go eat first!"

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(End of this chapter)