Common faults of electric control engine of the ho

Common faults of automobile electronic control engine

electronic control engine is an intelligent control engine equipped with computers, sensors and actuators. The biggest difference between electronic control engine and carburetor engine lies in the fuel supply. The carburetor has been canceled in the fuel supply system of the electronically controlled engine, but many electronic automatic control devices have been added

the electronically controlled engine should not only complete the tasks that the carburetor needs to complete, but also complete the tasks that the carburetor is difficult to complete. For example, let the narrow fuel specific concentration of the combustible mixture be controlled within the required range, so that the combustion is more sufficient and the exhaust pollution is significantly reduced. Because the electronic control part is added in the fuel supply system of the electronically controlled engine, the oil circuit and circuit are interconnected, which not only affects the work of the engine fuel system, but also affects the normal operation of the engine. It is also because the increase of electronic control devices of electronically controlled engines makes the whole mechanism of the engine more complex

the electronically controlled engine also has the following advantages: the electronically controlled fuel injection system can optimally control the fuel injection parameters (such as fuel injection quantity, fuel injection timing, fuel injection pressure, fuel injection rate, etc.) according to the different operating conditions, and can consider the impact of various factors on the performance of the diesel engine; It has complete control functions; It has high control accuracy and fast dynamic response; It can effectively improve the power, economy and emission performance of the engine; Provide fault diagnosis function to improve reliability by 1. After a certain amount, it will be aggregated into a volume

due to the extensive use of electronic control technology in modern vehicles, its electrical equipment and system structure are becoming more complex and precise, making the performance of vehicles more perfect. At the same time, there are higher requirements for vehicle fault diagnosis and maintenance. Therefore, the power of fault diagnosis and maintenance of the electric control engine. However, it is necessary to make full use of technical maintenance data, think and analyze carefully, judge the scope of the fault, and solve the problem of the fault in a targeted manner in combination with the original fault, phenomenon and test results

common faults of electronic control engine are as follows: difficult starting and unstable speed; Unstable idle speed of hot car; Engine backfire; Weak engine operation; The engine has intermittent faults; Lack of cylinder surge; Excessive fuel consumption

; Poor acceleration and other symptoms. There may be many reasons for each failure

1 main reasons for difficult starting

(1) low starting speed, check the battery power supply, circuit contact, starter status, etc

(2) poor ignition system and abnormal high-voltage spark

(3) insufficient oil supply and blocked oil outlet of fuel pump

(4) the cold start injector and its control circuit are poor

(5) poor idle speed compensation system

(6) improper ignition time, too early or too late

(7) poor water temperature sensor

(8) the air intake system has serious air leakage and the mixture is too thin

(9) the electrical plug is loose and the component does not work

2 main reasons for unstable idle speed

(1) there is a problem in the intake system, which makes the mixture too thin

(2) the auxiliary air valve does not operate normally

(3) uneven injection of fuel injector

(4) the ignition time is incorrect or. There is a problem with the ignition system

(5) incorrect valve clearance

(6) oil leakage of cold start injector, etc

frequently used terms:

3 main reasons for weak engine operation

(1) low fuel pressure and poor fuel supply

(2) poor ignition system or improper ignition timing

(3) poor engine compression system

(4) insufficient air flow meter or intake pressure sensor

(5) the engine is seriously worn and the cylinder compression force is insufficient

4 the competitive advantage of the engine with intermittent faults is basically the reason for the low-level comparative advantage supported by cheap labor

(1) the wire connectors are loose and tightened firmly item by item

(2) check the ignition system and high-pressure sparks of each cylinder

(3) check the status of odd distributor

(4) check whether there is air leakage in the odd vacuum tube

(5) artificially vibrate and observe whether the fault phenomenon changes

5 causes of unstable idle speed of hot cars

(1) the idle speed control valve or its circuit is poor

(2) poor oxygen sensor

(3) hot car has no correction signal

(4) poor water flow sensor

(5) poor exhaust gas recirculation system

(6) poor ignition system

6 the causes of engine backfire are:

(1) the mixture is too thin and the combustion speed is slow

(2) the ignition system is poor or the ignition time is too late

(3) poor fuel supply system and insufficient fuel supply

(4) the air intake system leaks and the mixture is too thin

(5) "Li Pengjun, director of Haier New Materials Marketing Department, said that the valve clearance was improper and the valve action was abnormal

(6) the exhaust system is blocked

(7) the ignition sequence is disordered

how can we remove the false and retain the true from so many fault causes, and quickly and accurately find the original prisoner of the fault? To do this, we really need to master the structure and principle of the engine. Especially for the engine electric control system with complex structure, we must have a comprehensive understanding of the functions of various sensors and the engine faults that may be caused by the sensor failure