2013 Chevrolet Cruze lack of cylinder maintenance

Fault phenomenon: the engine idle speed is basically normal, the gas discharged from the exhaust pipe is relatively uniform, there is no cylinder shortage Yanhua acdp phenomenon, but when the vehicle accelerates, the engine power obviously has the jitter caused by the lack of cylinder, especially when the acceleration is above 3 gears, the phenomenon More obvious.

The fault code is read by the decoder and displayed as "P0300", and the engine is out of cylinder. Then read the misfire data in the data stream, indicating that the 3 cylinders will be short of fire when accelerating, and the record has been increasing. The other 3 cylinders are normal. The spark vvdi bmw plug was removed and there was no obvious abnormality. First, according to the experience of the previous test, replace the new ignition coil, the test failure still exists.

The vehicle exhaust gas is detected. The purpose of the test is to judge whether the cylinder is missing due to no ignition or because there is no cylinder caused by fuel injection. The idle car works normally, and there is no other fault code. There is only one P0300. The analysis thinks that the mechanical system is not a big problem. The fault may be in the ignition system, but the owner said that the new spark plug has just been replaced in other repair shops.

Fault summary: This car failure is caused by the spark plug leakage, because it is a new spark plug, so it is confirmed that the spark plug quality problem. Through the exhaust gas analysis, we saw that the abnormal increase of the main component HC. In experience, O2 should rise, but not seen in this car, it should be the catalytic and reduction of the three-way catalytic converter to consume the oxygen that is not cardiag burned inside the cylinder, let the oxygen participate in the combustion, and finally did not look at O2. The data appears. This reminds us that in the diagnosis of faults, it is most effective to combine experience and data for analysis and judgment. The most important thing is that through the above tests, we found the cause of the failure, and after the repair, the data was used again to prove that the repair was effective.