Tempering performance and troubleshooting of engine intake pipe

What is the tempering of the intake pipe of EFI engine? How to deal with it? And car muffler "shot" is what phenomenon? The following small series introduces the muffler "shooting" phenomenon in the troubleshooting of intake pipe tempering of EFI engine.

[Tempering performance of engine intake pipe]

The engine is not working properly. When the throttle opening increases rapidly, the intake pipe backfires and the engine is weak.

The valve overlap angle of throttle gasoline engine is too large, which causes the phenomenon that high temperature exhaust gas flows back to the intake pipe to ignite combustible mixture.

The analysis and elimination methods of engine intake pipe tempering fault are as follows:

(1) Air leakage in the intake system leads to too lean mixture and slow combustion speed. When the intake valve is opened, there is still gas burning, which is easy to cause the intake pipe to backfire.

(2) The ignition time is too early.

If the intake valve is not closed properly, the mixture will start to burn, which will easily cause the intake pipe to backfire. Check the ignition time. If it is too early, adjust it.

(3) low injection pressure

Check the fuel pressure. If the oil pressure is low, the fuel injection quantity will be reduced, and the mixture will be too thin, resulting in tempering of the intake pipe. Check the fuel pressure regulator to see if the fuel filter or oil circuit is blocked; Check the operation of the fuel pump.

(4) The injector is not working properly.

Remove the fuel injector, and check its fuel atomization, fuel injection quantity, oil dripping quantity and starting voltage value of the fuel injector.

(5) Check the cold start injector.

If the fuel injector does not work, the engine will backfire during cold start. Check the working condition of the fuel injector, terminal voltage of the wiring harness, temperature and time switch, etc.

(6) Inspection of electronic control system

Includes checking an air flow sensor or a manifold pressure sensor; Check the resistance value of the water temperature sensor; Check the air temperature sensor; Check the throttle position sensor; Check oxygen sensor, etc.

In addition, check whether the spark plug is on fire and whether the battery voltage is normal. If the above conditions are normal, check whether the intake valve is well sealed.

Diagnostic process: when the engine backfires, that is, the mixture is too thin, it can be diagnosed.