The spray printing system used in spray processing is electronically controlled fuel injection. The basic feature of this fuel-injected engine is that the working laser cutting of the engine is monitored in real time by the computer control unit, which is mainly based on the amount of air taken in by the engine, air temperature, cooling water temperature, Various sensor information such as throttle opening, exhaust oxygen concentration, engine speed, explosion degree, etc., control fuel supply, ignition advance angle, and make the engine work in the best state. Therefore, the fuel injection system failure inspection and the electronic fuel injection system The judgment is based on this feature, and fault diagnosis is carried out based on the basic working principle of the engine.
General procedure for troubleshooting of EFI system
Ask the user about the operating conditions, conditions, and failure phenomena when the fault occurs. The inquiries should be as detailed and comprehensive as possible, and well recorded. Ask about the usage of the vehicle, such as mileage, time experience, etc., and make a record.
2. Read the fault code
Use the self-diagnostic system to read the fault code. The fault location recorded by the fault code of the self-diagnosis system is an important basis for fault judgment. Correctly reading the fault code is the key to repairing the EFI system. Since the fault code is stored in the control unit, the code will still be stored in the control unit memory if it is not cleared after maintenance. Therefore, it should be noted that after reading the code completely and verifying the fault, remove the code of the fault that does not exist.
3. Reproduce the failure phenomenon
When the cause of the failure cannot be determined or the phenomenon is not clear, a failure reproduction test shall be carried out. According to the fault clues provided by the user, imitate the working conditions, conditions and environment of the fault to verify. The most commonly used are normal operation test, full load operation test, vibration method, heating method, water shower method, etc.
(1) Running test to reproduce faults
According to the results of the consultation, carefully analyze the conditions of the failure and conduct a road test until the failure occurs. If necessary, according to the working conditions at the time of the failure, all electrical appliances can be connected for a full-load driving test.
(2) Vibration method to reproduce failure
The vibration method is to gently shake the connection line and tap the connector and sensor with your hand to promote the reappearance of the fault. This is the main method for judging the failure of automobile electrical appliances. It is often used to check for poor wiring connections and malfunctioning relays.https://www.ptjmachining.com/
①Connector: Shake the connector gently in the vertical and horizontal directions.
② Wiring: gently shake the wiring in the vertical and horizontal directions. The joint of the connector, the vibration bracket and the connector body through the opening are all parts that should be checked carefully.
②Parts and sensors: Tap the parts with the sensor with your fingers to check whether they are malfunctioning.