Step on the accelerator deeply, without accelerating, the speed soars. You will feel helpless and ask for help.

EFI engine uses electronic control device instead of traditional mechanical system (such as carburetor) to control the fuel supply process of the engine. For example, the EFI system of a gasoline engine inputs signals such as engine temperature, air-fuel ratio, throttle condition, engine speed, load, crankshaft position, vehicle running condition, etc. into the electronic control device through various sensors. According to these signal parameters, the electronic control device calculates and controls the fuel injection quantity and time required for each cylinder of the engine, and sprays gasoline into the intake pipe through the fuel injector at a certain pressure for atomization. It is mixed with the incoming airflow and burned in the combustion chamber, thus ensuring that the engine and catalytic converter always work in the best state. What are the factors that affect the fuel economy of automobiles? There are many factors, including the vehicle itself, the driver and the road conditions. Generally speaking, there are seven aspects: engine, emission, transmission, body modeling, weight, tires and driving technology. Although road conditions have a great influence on fuel economy, such as unblocked and blocked, urban and expressway driving will have a direct impact on fuel consumption, but road conditions will change at any time, so they are not included in the main influencing factors. 1. Cause of failure 1) The air filter is blocked or the idle speed is not adjusted properly. 2) The hot air valve is blocked or the ignition time is too late. 3)EFE heater is not working properly or the oxygen sensor is faulty. 4) The exhaust system is not working well or the tire pressure is insufficient. 5) The ventilation valve of 5)PCV crankcase is blocked or the filter is not clean. 6) The injector is blocked or leaked during cold start. 7) Internal damage or serious wear of the fuel injector. 8) Driving or parking brake delay. 9) The ignition time is adjusted too late. 10) The thermostat of the cooling system is faulty or the control temperature is too low. 1 1) There is something wrong with the constant temperature air filter, which keeps the hot air from getting in. 12)EGR recirculation valve is normally open due to sticking. 2. Troubleshooting 1) Check the tire pressure and braking technology. 2) Check the air filter. 3) Check the condition of fuel, oil pump and filter. 4) Check the oil pressure, oil supply and regulator. 5) Check the connection between the fuel injector and the engine piping system. 6) Check the coolant temperature sensor and air temperature sensor. 7) Check the air flow sensor and throttle position sensor. 8) Check the connector of knock sensor and ECU. 9) Check the thermostat, constant temperature air filter and EGR recirculation valve of the cooling system. Symptoms of replacing the spark plug: After the performance of the spark plug becomes worse, the engine will feel insufficient power when driving, the car will accelerate rapidly and the exhaust pipe will make a "sudden, sudden" sound, and the engine will shake when idling. Solution: It is recommended that you go to the repair shop to check the spark plug every 30,000 kilometers and replace it if necessary. Symptoms and signs of dirty throttle body: When the throttle of Mercedes-Benz W 140 car runs about 20 thousand kilometers, there will be a lot of dirt at the cut-off valve due to air quality. When dirt accumulates to a certain thickness, it is not easy for the engine to hit the car when it starts, and the engine will decelerate abnormally after hitting the car, and the throttle will turn off when driving. At this time, it is necessary to clean the throttle. Solution: After cleaning, set the original diagnostic instrument to reach the standard. Symptoms of cleaning the injector without disassembly: after the injector is dirty, the engine will have difficulties in starting, power drop, slow acceleration, idling jitter, black smoke and excessive exhaust, and in severe cases, the engine will not start. Solution: The disassembly-free cleaning of the fuel injector can also clean the carbon deposit on the top of the combustion chamber and piston. It is recommended that the vehicle should not be disassembled and cleaned once every 20,000 kilometers. This can also avoid the thick accumulation of carbon deposits in the intake system. Symptoms of oil leakage from steering gear: After the repair kit of automobile steering gear with W 140 chassis is damaged, there will be a lot of oil stains on the outside of steering gear, resulting in the loss of steering power oil. It will make a lot of noise when turning when it is seriously short of oil. If it is not repaired in time, the booster pump will be damaged due to lack of oil. Solution: If the steering gear leaks oil, it should be replaced at the repair shop in time to prevent the steering power system from being damaged due to oil leakage. Generally, vehicles with W 140 chassis travel about 65,438+10,000 kilometers, and the steering gear leaks more oil. Symptoms of water pump damage and coolant leakage: it is common for W 140 vehicle water pump to leak coolant. Water pump damage, coolant leakage and serious coolant loss will cause the coolant temperature to be too high and damage the engine. Solution: If it is found that the water pump leaks coolant, it should be replaced in time to avoid further losses. Fault symptom of fuel pump: The fuel pump delivers fuel to the injector under pressure. Generally, the fuel pump of Mercedes-Benz W 140 chassis will make a "squeaking" sound before it is damaged. When the fuel pump is damaged, the fuel cannot be injected into the engine, and the engine will stop working. Solution: When the fuel pump has abnormal sound, it should be replaced in time to prevent the car from breaking down. Fault symptoms caused by brake switch damage: The car with ASR system in W 140 will light up the ASR light after the brake switch is damaged, and sometimes it cannot accelerate when driving. Solution: When the ASR light is on, you should go to the repair shop and check it with a diagnostic instrument. Generally speaking, due to the brake switch, the ASR light will light up more. Symptoms of air flow meter failure: Use hot film air flow meter to measure the amount of air inhaled by automobile engine equipped with ME injection system. Because of its structure, the air flowmeter is particularly easy to be damaged. After the damage, the vehicle appears to be unable to accelerate, emit black smoke, cannot run to the maximum speed, has no idle speed and so on. Solution: It is suggested to clean or replace the air filter in time according to the driving air condition. Only by constantly keeping the dust content of the air entering the engine low can the life of the air flowmeter be prolonged. 1) Check the tire pressure and braking technology. 2) Check the air filter. 3) Check the condition of fuel, oil pump and filter. 4) Check the oil pressure, oil supply and regulator. 5) Check the connection between the fuel injector and the engine piping system. 6) Check the coolant temperature sensor and air temperature sensor. 7) Check the air flow sensor and throttle position sensor. 8) Check the connector of knock sensor and ECU. 9) Check the thermostat, constant temperature air filter and EGR recirculation of the cooling system. Discussion on fuel consumption of EFI engine. There has been a long debate about the horse's engine and fuel consumption in the cylinder. Obviously, everyone is very concerned about this issue, but the Jockey Club and even the whole Aika can't talk clearly. Now I'm going to try. At present, the cars that most of us can touch are nothing more than carburetor engines or EFI engines. Nonsense, everyone knows this! But why should carburetor be eliminated by EFI? Because EFI is more energy efficient than carburetor? P, does everyone know that EFI in our country is more fuel-efficient than carburetor with the same displacement? Why should carburetor be changed to EFI? Environmental protection requirements. Start telling a story: 1. Concept of engine: The engine used in automobile is called internal combustion engine, which refers to the use of fuel in a closed environment. Sufficient air is the absolute prerequisite for the full combustion of fuel, but because it is a closed environment and the air is quantitative (so-called displacement), it is reasonable to add quantitative fuel to quantitative air, which is simple to say and difficult to realize. Because the working principle of the engine is complicated, what ordinary people need to know is that the engine is variable in power, and it outputs different power through different piston motion cycles (so-called rotational speed). Although we can fix the displacement to a numerical value, the rotational speed is a variable, not a nonlinear variable, and the carburetor is a purely mechanical structure. The fuel supply is linearly proportional to the throttle, and the fuel supply is purely manual, so it is difficult to achieve reasonable quantitative fuel supply. In the past, novices were prone to flooding when driving, which is the reason. On the other hand, because of man-made, endless fuel-saving schemes, most of them are practical and effective, but I want to shout here-it's useless for EFI! The application of EFI technology solves the contradiction between fuel and air, and makes fuel and air burn reasonably and fully. Its remarkable feature is that it greatly reduces the exhaust emissions. So the difference between carburetor and EFI is: structural difference: oil supply system. Target difference: reduce emissions. Second, the concept of EFI engine: the so-called EFI is to automatically supply oil to the engine through the electronic control system, completely getting rid of human control factors. I believe many people will feel like falling into the well when they see this place. What should I do when I step on the accelerator while driving? Give everyone a brand-new term "throttle no, throttle pedal yes". The working principle of EFI is roughly as follows: the air volume is recorded by an air flow sensor, and the oil supply is determined according to the air volume. At the same time, an exhaust gas sensor is set at the exhaust, which records the amount of exhaust gas and feeds it back to the oil supply system. Through this complete cycle, the fuel is fully burned and the emission is minimized. But the problem is not that simple. Cars are moving, for example, the movement of cars or the natural wind in the environment will cause changes in airflow. In order to avoid the ridiculous thing that the car stops at a red light and blows a gust of wind and the engine turns around, the working mode of the EFI system is zigzag intake and sampling, that is, the intake pipe of our horse is designed as a zigzag head, and the accelerator pedal changes the airflow. Similarly, EFI needs to solve the problem of power output, but there are many and complicated factors affecting power output, such as environment (temperature, airflow, etc. ), road conditions (road quality and ups and downs, etc. ), car condition (tires and loads, etc. ), and man-made (driving habits and methods, etc. ). How does EFI solve these problems? Through sensors such as temperature, the temperature sensor can sense the temperature, so as to control the electronic fan and thermostat to adjust the temperature. Due to the limitation of space, I can't list all the sensors. It can be said that a more complete description of EFI engine is body+sensor+controller+central system. As we all know, the factors that determine the quality of EFI engine have shifted from simple cylinder volume to the quantity and quality of sensors, controllers and central systems. I am very sad, because China can't develop its own sensors and central system at present, giving people an appearance that even the engine can't be built; I am angry, manufacturers are greedy for profits, withdraw more and tear down less and replace the old ones, and make a big fuss about EFI sensors, controllers and central systems; I am very helpless, the majority of riders know nothing about engines, seeking low prices to catch up with benefits, and the middle set is also counting money for others. Third, the concept of engine fuel consumption: forgive me for talking too much. Most of the so-called fuel consumption problems discussed in the jar are extremely boring, and their essence is actually like those retarded people who use fans or air conditioners on hot days. Why do you say that? Because manufacturers and the media have changed their ideas, most of them are intentional and confused. Most of the media are ignorant and make a living from it. Everyone knows that the so-called fuel consumption index of a car is liter/100 kilometers, but this index is actually meaningless. Just as you ask me how much I eat, I can definitely answer: four or two. But at most, when you invite me, you can use this as a reference for the amount of food, and you won't deliberately pursue these four two! Why do people care so much about the fuel consumption per 100 kilometers? Everyone thinks that the fuel consumption index is an important indicator to judge the performance of the engine, yes, but it is wrong to use liters/100 kilometers! Just like you asked me about my appetite, I replied: four Liang. And it's equally ridiculous for you to infer my health from this. What's the trick about this liter/hundred kilometers? In China, we should erase all the good and bad engines! For example, if you put a horse's engine on a Bora car, the engine index is not 5.7( 1.6 displacement), but 6-7, and the actual fuel consumption will be more than 12, because the dead weight of Bora is much larger than that of a horse! And we look at the existing 65438+ 10 million models. We use different engines and have different self-weights. But we clamored for the index of "up/100 kilometers" to cheat the so-called economy. If the weight is less than 30 kg, the index can be reduced by several percentage points. However, the manufacturer will not say that this 30 kg is to save two anti-collision steel beams on the door side, but that the engine saves fuel! Well, what really reflects the quality of the engine is the output power and emission index. The output power indicates the fuel utilization rate, and the emission index indicates the quality of the EFI system, that's all. I declare here that I am in contact with 1.6GLS, but I am not clear about 1.3 because of time and energy. Excuse me! Look at this horse's engine. It is the only one in China with a price of 6.5438+10,000 yuan and listed globally at the same time. In the United States, it is Euro 4, with automatic cruise and engine locking. Go to Sohu or Sina to see the indicators. Fourth, the concept of fuel saving for EFI vehicles: As I mentioned in the article, in our country, EFI with the same displacement is more fuel efficient than carburetor, with the aim of increasing/100 kilometers. Upgrading the engine from carburetor to EFI is a technological progress, not a technological leap. Although EFI improves the use efficiency of unit fuel, it inevitably increases the load of the engine in disguise, and the safety and comfort of the vehicle are also constantly improving. The increase of audio and air conditioning power consumes the boosted power without exception, which is an objective reason, while the low quality of sensors and controllers will reduce the power of the central system, which is a subjective factor. For example, the temperature sensor can't accurately measure the temperature, the thermostat can't be effectively adjusted, and the electronic fan often starts unnecessarily, and the electronic fan is a big power consumer, so the oil consumption is naturally high. Therefore, EFI can only reflect the environmental protection effect. The most important factor to determine the fuel consumption of EFI is the advanced degree of central system, including numerical value and control degree. A simple example is the difference between 286 and Ben 4. Because the content is too complicated, I won't talk nonsense here. It can be seen that the fuel-saving method of EFI vehicles requires people to adapt to EFI characteristics as much as possible, rather than relying on operating skills, including driving skills and carburetor adjustment skills, like carburetor. If we put aside the reasonable requirements of air conditioning, audio, load and whether the tire pressure is normal, the only way to save fuel for EFI vehicles is to shift gears strictly according to the vehicle speed; Accelerate to the economic speed as soon as possible, and keep it when conditions permit; Step on the brakes less.