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

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

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

② Check whether the ECU connector is securely connected;

③ Replace the ECU.

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 renew the pressure of the oil pipe, and whether the working sound of the oil pump can be heard;

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

(3) Connect the diagnostic instrument to check whether there is a fault code. If there is, check whether the relevant original device is not installed in place, the connector is not plugged tightly or is damaged according to the indication of the fault code;

④ Whether the high pressure pack can jump fire normally, and whether the spark plug is flooded or has too much carbon. If the spark plug does not jump fire, please check whether the wire harness plug-in of the high pressure pack is securely in contact;

⑤ Check whether the injector is sprayed during the running of the starting motor. If not, please check whether the 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 high, low or unstable

① Cylinder temperature is lower than 60℃, the system set idle speed is 200 RPM 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 be sealed with paper pads, and the sealing ring can replace the paper pad), whether there is air leakage at the connection between the intake pipe and the valve body;

(3) Consider whether the stepper 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, repeated operation for 3 times;

(4) When the engine is running, the instrument failure light is steady on, and the diagnostic instrument is used 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. Whether the current [battery voltage] is between 12V-15V, if not, the battery power loss, the EFI system can not work normally, check the magneto, rectifier and other power generation components;

c. Whether the current [stepper motor opening] is greater than 15 steps, if it is too small, 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 feedback flag] is YES; If it is NO, check whether [neutral switch mark position] is YES(when the vehicle with gear position is in neutral, it should be YES).

3. Fault phenomenon: the idle speed is unstable, the sliding under break is stalling, and the high-speed throttle is easy to stalling

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

(2) After the engine starts, the instrument failure light is off, indicating no fault, if it is steady on, indicating a fault;

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

④ Check whether the spark plug has too much carbon deposit and drowning 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. Hot car idle speed [intake pressure] is too large (compared with normal vehicles more than 5kpa), check the intake and exhaust valve clearance;

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

⑥ If the engine is turned off during sliding, use the diagnostic instrument to enter the [YESON special expansion data] to check whether the [stepper motor opening] continues to decay, if the stepper motor opening continues to decrease to less than 10 resulting in flame failure, please check whether the neutral signal is normal, and whether the clutch handle switch signal is normal.

4. Fault: The acceleration is poor

① Check whether there is a fault in the vehicle, and whether the parameters of [YESON special expansion data] are normal when idling;

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 symptom: Fuel consumption is abnormally high

① Check whether the oxygen sensor is installed in place, if the oxygen sensor is not tight, the oxygen sensor misjudged the mixture to be thin, thus increasing the fuel, and eventually leading to abnormally high fuel consumption;

② Check whether the oxygen sensor is damaged;

③ Check whether the inlet and exhaust valve clearance is appropriate.

6. Fault phenomenon: The vehicle cannot start, but the diagnostic software reports a lot of actuator faults

The diagnostic software reported a lot of fault codes, such as ignition coil, injector, oxygen sensor heating, etc., are the fault of the actuator, and it is necessary to check the ECU relay to check whether the wire on the relay has fallen off, resulting in the power supply failing to input the actuator, so that the actuator has no voltage and fails.

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