Troubleshooting of automobile exhaust pipe exhaust instability
  • Automotive

After the cold car starts, the exhaust pipe of the Bora 1.8 model is unstable, and the engine jitter time is longer. After the cold start of the engine, the engine control unit is to maintain normal combustion and steady idle speed, and does not regulate the lambda. The fuel injection quantity of the injector is very large, the mixture gas is thicker, the mixture gas is not burned completely, and the exhaust emission is serious. In order to reduce the tail gas pollution at the start of the cold car, two air injection devices were installed on the Bora 1.8 and 1.8T cars. At the warmer stage, the two air ejector sprayed fresh air into the exhaust pipe of the engine to continue the combustion of the combustible components in the exhaust gas in order to reduce the emission of pollutants and achieve the Euro III emission standards. The time of the two air injection depends on the coolant temperature. The longest time does not exceed 100s. In the two air jet, the exhaust pipe exhaust is unstable, but the instability will not exceed 100s, the unstable time in summer is shorter, and the unstable time is longer in winter, but it is all normal. If the exhaust is unstable and the engine is jitter for a long time, it may be caused by excessive carbon accumulation in the valve, valve seat and combustor. But the first step is to query the fault code and read the data flow, if the problem should be eliminated first, then other diagnosis or troubleshooting, such as cleaning carbon (playing the bottle) and the fuel system free cleaning. Using the fault diagnosis instrument V.A.G1551, there is no memory fault code, and the data flow is normal. Then the carbon deposition and fuel system were removed and cleaned, and the exhaust time of the exhaust pipe was shortened during the warm-up stage.