Eaton Char-Lynn Motor - Motor Idle Jitter: Several Reasons
Added: (Thu Mar 21 2019)
Pressbox (Press Release) -
Because the motor's idle speed will affect the performance of the motor, increase the fuel consumption of the motor, reduce the reliability and life of the motor, if the maintenance is not timely, the motor performance will be further deteriorated, and even more faults will be caused. Therefore, the analysis of the causes of idling jitter faults is particularly important.
Eaton Char-lynn Motor description: The cause of idling jitter is complicated. If you encounter such problems, you should analyze it from the following aspects.
1. Intake system failure
(1) Excessive fouling of the throttle valve or intake port or blockage of the air filter element
Excessive fouling of the throttle valve or intake port or blockage of the air filter filter element, the cross-sectional area of the idle passage becomes smaller, the amount of air entering the cylinder is less than the normal value, the mixed gas becomes rich, and the cylinder combustion is insufficient, resulting in motor shake.
(2) Intake line or EGR valve leakage
The intake pipe or the EGR valve leaks, the amount of air entering the cylinder is greater than the normal value, the mixture gas is thinned, and the cylinder power performance is degraded. If the EGR valve is not closed tightly, some of the exhaust gas will enter the cylinder, the residual exhaust gas will be high, the combustion condition will be deteriorated, and the motor power will be reduced to cause the motor to shake.
(3) Air flow meter or intake pressure sensor failure
If the air flow meter or the intake pressure sensor fails, the intake air quantity will not be accurately measured, and the injection quantity of the fuel injection system will be out of alignment, resulting in an abnormal amount of air entering the cylinder, and the concentration of the mixed gas is uncertain, causing motor shake.
(4) Idle speed control system failure
The idle speed control system mainly controls the intake air amount at idle speed, and the fuel injection amount is increased or decreased according to the amount of intake air to achieve a suitable air-fuel ratio, if an idle speed control system (such as a throttle position sensor, an idle speed valve, etc.) In the event of a failure, the motor will not be able to achieve accurate air-fuel ratio control, resulting in motor power performance degradation, resulting in motor shake.
2. Fuel system failure
(1) Oil supply pressure failure
There are many reasons for the oil supply pressure failure: fuel filter blockage; fuel pump damage or filter blockage; fuel pump pump oil pressure is insufficient; fuel pump safety valve spring force is reduced; fuel pressure regulator damage. If the fuel supply pressure is abnormal, the mixture is too rich or too lean, the motor power performance is degraded, and the motor is shaken.
(2) injector failure
Common faults of the injector include: injector coil damage; injector stuck; injector blockage; injector seal failure. Injector failure will result in uneven fuel injection and poor atomization of each cylinder, resulting in uneven output power of each cylinder, causing motor shake.
3. Ignition system failure
(1) Spark plug
The spark plug can introduce high voltage electricity into the combustion chamber of the motor and generate an electric spark between the electrodes to ignite the combustible mixture. If the spark plug electrode gap is incorrect, the spark plug electrode is carbon or ablated, the spark plug insulator is cracked, etc., the spark plug may not jump or the spark energy is weak, resulting in poor combustion of the mixed gas, motor power imbalance, motor The situation of jitter.
(2) ignition module or ignition coil
Failure of the ignition module or ignition coil can also result in non-flashover or weak spark energy, which can cause motor shake. At present, most of the vehicle's ignition module and ignition coil are made in one piece.
(3) Ignition control circuit, ignition timing
In a computer-controlled ignition system, the ECU receives signals from various sensors and other devices related to motor operating conditions, performs calculations, analysis, and judgments, and then issues commands to the executing device to achieve ignition control. A fault in the sensor or ignition control circuit and an erroneous command from the ECU result in an incorrect ignition advance angle. Common causes are: air flow meter or intake pressure signal failure; coolant temperature sensor failure; intake air temperature sensor failure; Hall sensor failure; poor motor control unit contact or internal circuit damage.
4. Electronic control system failure
The electronic control system mainly determines the optimal injection quantity and ignition advance angle of gasoline based on motor operating conditions and vehicle operating conditions. The system consists mainly of sensors, actuators and ECUs. The sensor collects various data in the motor operation and sends it to the ECU for processing to better control the fuel injection and ignition of the motor. If the sensor data collected by the ECU is deviated, the ignition or fuel injection may be deviated, and the motor cannot normal work. The control computer is the core component for controlling fuel injection and ignition. The common fault of the control unit is internal circuit damage or poor contact.
5. Mechanical structure failure
(1) Piston connecting rod mechanism and motor body
Common faults of the crank-and-rod mechanism include: damage or loss of elasticity of the piston ring, carbon deposit in the piston ring groove, carbon deposit in the cylinder, bending deformation of the connecting rod, and the like. These faults also cause unbalanced power in each cylinder and motor jitter.
(2) Gas distribution mechanism
Common faults of the gas distribution mechanism include: incorrect timing of the belt installation, misalignment of the valve phase, excessive carbon in the working area of the valve, resulting in poor valve closing, inconsistent cam wear, resulting in inconsistent air intake of the cylinder, and the valve spring is broken due to the valve spring being broken. These faults will cause the cylinder power to drop, the power of each cylinder to be unbalanced, and the motor to shake.
6. other reasons
Air conditioning systems, automatic transmissions, etc. increase the motor idle load and cause motor shake. Unbalanced rotating components such as three-way catalytic converters, crankshafts, and flywheels can also cause motor shake.
The main cause of idling jitter is that some factors cause power imbalance in each cylinder, causing motor shock and vibration, and idling jitter.
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