What are the common faults of electronic fuel injection diesel engines? How to diagnose and solve it?

　　Electronic fuel injection diesel engine is a type of diesel engine that adopts electronic control injection technology. It improves combustion efficiency and reduces emission pollution by accurately controlling fuel injection time and injection quantity. However, even the most advanced technology may encounter some common malfunctions. Below are some common types of faults in electronic fuel injection diesel engines, as well as corresponding diagnosis and solutions.

　　Common faults and solutions

　　1. Difficulty initiating

　　Symptom: The engine is difficult to start or requires multiple attempts to start.

　　Reason: There is a malfunction in the air or fuel supply system in the fuel pipeline.

　　Solution: Check and eliminate the air in the fuel pipeline to ensure that the fuel pump is working properly. For vehicles using a common rail system, it may be necessary to loosen the oil pump return bolt to exhaust air, and if necessary, loosen the high-pressure oil pipe to use the starter to drive the engine to idle to exhaust air.

　　2. Unstable idle speed

　　Symptom: Engine shaking or unstable RPM when idling.

　　Reason: The idle switch is not closed or there is a problem with the fuel injector.

　　Solution: Check if the throttle position sensor is working correctly and adjust or replace it if necessary. Check if the fuel injector is clogged or dripping, and clean or replace it.

　　3. Fuel injector malfunction

　　Symptom: Fuel injector dripping or blockage.

　　Reason: Internal parts of the fuel injector are worn or blocked.

　　Solution: Use professional tools for inspection, and replace the fuel injector if necessary. Usually requires professional technicians to perform the operation.

　　4. Electrical system malfunction

　　Symptom: The starter motor is not functioning properly.

　　Reason: Insufficient battery power, loose starter head, worn electric brush, etc.

　　Solution: Check the battery level to ensure sufficient starting voltage. Check if the starter connection is secure and if the brush contact is good. If necessary, replace the brush or repair the starter.

　　5. Fuel system issues

　　Symptoms: Decreased engine power or increased fuel consumption.

　　Reason: Improper installation of fuel pump or clogged fuel filter.

　　Solution: Check the installation of the fuel pump to ensure it is correct and error free. Regularly replace the fuel filter to maintain the smoothness of the fuel system.

　　6. Abnormal noise

　　Symptom: Abnormal noise occurs during engine operation.

　　Reason: The clearance between the piston and the cylinder wall is too large, and the assembly of the piston pin is too tight.

　　Solution: Check the gap between the piston and the cylinder wall, adjust or replace the relevant components.

　　Diagnostic methods

　　Electronic diagnostic tool: Use specialized diagnostic instruments to read fault codes and help locate problems.

　　Physical inspection: Manually inspect the appearance and connection of components, such as checking for loose joints.

　　Test run: Run the engine under specific conditions and observe its performance.

　　Replacement method: Replace suspected faulty components to determine the source of the fault.

　　In summary, the fault diagnosis of electronic fuel injection diesel engines usually involves multiple aspects of inspection and testing. For some complex faults, it is recommended to seek professional maintenance services to ensure safe and effective problem-solving.