1. Fault phenomenon: After opening the key, the starting motor can work normally, but the engine can not start

A. If the flameout switch is turned on, whether the fault light on the instrument is on or the oil pump is working, if the light is not on and the oil pump is not working (indicating that the system is not working) :

(1) Check whether the fuse, grounding wire and battery positive and negative wires are securely connected;

② Check whether the ECU connector is securely connected;

③ Replace the ECUs.

B. If the fault light can turn on normally, please check:

(1) Whether the oil pump works, after opening the key, the oil pump will work for 4 seconds to refill the oil pipe pressure, whether you can hear the working sound of the oil pump;

(2) Whether the fuel in the tank is enough (completely submerged oil pump screen), whether there is air in the oil pipe;

(3) Connect the diagnostic instrument to check whether there is a fault code. If there is, check whether the relevant original devices are not installed in place, the connectors are not plugged in tightly or are damaged according to the instructions of the fault code.

(4) Whether the high voltage packet can normally fire, whether the spark plug flooded cylinder or excessive carbon, if the spark plug does not fire, please check whether the wire harness plug-in of the high voltage packet is secure;

⑤ Check whether the fuel injector is injected during the running of the starting motor. If not, please check whether the fuel injector plug-in is firmly in contact; ⑥ If the spark plug does not jump, and the injector does not spray oil, please check whether the magneto trigger coil signal is normal.

2. Fault phenomenon: the idle speed of the engine is on the high or low side or unstable

① If the cylinder temperature is lower than 60℃, the idle speed set by the system is 200 revolutions higher than the idle speed of the heat engine;

(2) Check the connection between the intake pipe and the cylinder head (both sides of the heat insulation pad need to add paper pad seal, sealing ring can replace the paper pad), the intake pipe and the valve body connection whether there is air leakage phenomenon;

(3) Consider whether the stepping motor is out of step, and whether the battery is seriously lost; After the battery is connected, open the shaft lock key and then close the key. Wait 5 seconds for the stepper motor to reset, and repeat the operation for 3 times;

(4) When the engine is running, the instrument fault light is steady on. Use the diagnostic instrument to check the specific fault information and repair the fault;

⑤ If the instrument failure light is not on and there is no fault, check whether the engine parameters are normal after entering the YESON special expansion data with the diagnostic instrument (check after starting the engine) :

a. Whether the current [throttle opening] is between 12%-15%, if not check whether the throttle cable is too tight, adjust the throttle position sensor screw;

b. Check whether the current [battery voltage] is between 12V and 15V. If it is not, the battery loses power and the electric injection system cannot work normally.

c. Whether the current [stepper motor opening] is greater than 15 steps, if smaller, there is the possibility of air leakage, check the valve body and intake pipe air tightness; e. Whether the current [idle status flag] is YES; If NO is used, check whether the grounding positions of ECU 3# and 19# are secure. f. Whether the current idle speed feedback flag is YES; If it is NO, check whether [neutral switch mark position] is YES(it should be YES when vehicles with gears are in neutral).

3. Fault phenomenon: the idle speed is unstable, the next break slide flameout, the high-speed throttle is easy to flameout

(1) Check whether the fuel is enough (completely submerged oil pump filter)

(2) If the instrument failure light is off after the engine starts, it means no fault; if it is steady on, it means fault;

③ Use the diagnostic instrument to check the specific fault information and repair the fault;

(4) Check whether the spark plug has excessive carbon accumulation, flooding cylinder phenomenon;

⑤ Check whether the engine parameters are normal after entering the [YESON special expansion data] with the diagnostic instrument (check after starting the engine) :

a. If the idle speed [intake pressure] of the hot car is too large (more than 5kpa larger than that of the normal vehicle), check the clearance of the intake and exhaust valves;

b. If the idle speed of the hot car [stepper motor opening] is too large (more than 15 steps larger than that of the normal car), check the clearance of the intake and exhaust valves; c. The clearance standard of inlet and exhaust valves is 0.08-0.1mm;

⑥ If the engine is flamed out when the engine is broken, the diagnostic instrument is used to enter the YESON special expansion data to check whether the [stepper motor opening] is constantly attenuated. If the stepper motor opening is continuously reduced to below 10, leading to flamed out, please check whether the neutral signal is normal, and whether the clutch handle switch signal is normal.

4. Fault symptom: Poor acceleration

① Check whether there is a fault in the vehicle and whether [YESON special expansion data] parameters are normal at idle;

(2) Check the amount of oil in the tank, check whether the exhaust system is blocked, check whether the pressure of the fuel pump is too low, and whether the fuel line is pressed at a discount;

5. Fault phenomenon: abnormally high fuel consumption

(1) Check whether the oxygen sensor is installed in place. If the oxygen sensor is not tightened, the oxygen sensor will misjudge that the mixture is too thin, thus increasing the fuel, and eventually leading to abnormally high fuel consumption;

② Check whether the oxygen sensor is damaged;

Check whether the clearance of inlet and exhaust valves is appropriate.

6. Fault phenomenon: The vehicle cannot start, but the diagnostic software reported many actuator faults

Diagnostic software reported a lot of fault codes, such as ignition coil, fuel injector, oxygen sensor heating and so on are the fault of the actuator, need to check the ECU relay, check whether the wire on the relay has fallen off, resulting in the power can not input the actuator, so that the actuator no voltage, failure.

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