Diagnosis and necessary treatment of several special faults of vehicles

Diagnosis and necessary treatment measures of several special faults of vehicles

1, unable to start.

1) Poor compressibility-Check compressibility and repair the engine if necessary.

2) Incorrect valve timing-Check the valve timing and correct it if necessary.

3) Ignition failure-Check and repair if necessary.

4) The fuel system, oil pump, fuel filter and injector are damaged, and the models of the injectors used do not match-check the fuel pressure and injector. Fuel pollution.

5) Three-way catalytic device is blocked

6) The oil pressure is too high-the oil drain valve or oil pump is faulty (resulting in the valve not being closed).

2. It's hard to start

1) Poor compressibility-Check compressibility and repair the engine if necessary.

2) Lean air-fuel ratio, vacuum leakage and fuel injector drum failure-check intake vacuum leakage and fuel injector.

3) The air-fuel ratio is too rich, and the fuel injector and input gear are faulty-check the fuel injector for fault diagnosis. Test the voltage and resistance of the input driver.

4) Fuel pressure regulator and fuel pump-check fuel pressure and fuel injector.

5) Ignition system failure-use an oscilloscope to check the ignition system.

3. Unstable idle speed

1) Deterioration of compressibility-Check compressibility and repair engine if necessary.

2) Exhaust gas recirculation valve (normally open)-Check the exhaust gas recirculation valve.

3) Vacuum leakage-check whether the air inlet pipe leaks.

4) Dirty syringe-Clean or replace the syringe.

5) Dirty throttle housing-clean the throttle if necessary.

6) There is dirt on the intake valve-clean the dirt on the valve with combustion chamber cleaning agent.

4. After the torque converter lockup clutch is locked, the engine is unstable.

1) spark plug, ignition lead and ignition coil.

2) Fuel injector, vacuum leakage and exhaust circulation valve.

3) Air flow sensor-Check the sensor and connecting wire.

4) Fuel pressure bottom-check fuel pressure and fuel pump flow.

5) The engine fixing bolt is loose.

6) oxygen transfer sensor failure

7) Throttle Position Sensor-Check the sensor and wires.

8) Poor compressibility of the air port-Check the compressibility of the engine.

9) Fuel pollution-check whether there is water and alcohol in the fuel.