Different types of poor ignition that produce burrs.

The poor ignition caused by unbalanced injection of nozzles is only in multi-point injection engines. The poor ignition caused by the rich or lean mixture of oil in one cylinder is caused by too much or too little oil actually injected by each nozzle (the nozzle is blocked or stuck). When the air-fuel ratio of air-fuel mixture in one cylinder or several gasolines exceeds the danger, poor ignition occurs when the air-fuel ratio exceeds 17: 1, and poor ignition occurs when the air-fuel ratio is lower than 13: 1, which results in poor ignition caused by unbalanced fuel injection from the fuel injector. In general, it can be judged by excluding the possibility of poor ignition caused by the ignition system, poor ignition of cylinder pressure and vacuum leakage of a single cylinder. Unbalanced fuel injection. The automobile oscilloscope can be used to eliminate the poor ignition caused by the self-ignition system and cylinder pressure (to find the poor ignition caused by the ignition system and the problem of dynamic balance cylinder pressure). To eliminate the vacuum leakage related to individual cylinders, propane (intake manifold, carburetor pad, etc.) is usually added to the area or surrounding where vacuum leakage may occur, and at the same time, as mentioned before, the signal waveform of oxygen sensor is observed from an oscilloscope to achieve the goal. Generally, in a multi-point fuel injection engine, if the misfire caused by types A, B, and C cannot be proved, then the possibility of imbalance causing serious clutter in the waveform of the oxygen sensor can be determined. Rules for judging the clutter of oxygen sensor If there is obvious clutter on the signal of oxygen sensor, which is abnormal for the judged system, it will usually be accompanied by repeated and testable engine failures at idle speed (for example, knocking at each cylinder ignition). Generally, if the clutter is obvious, the engine fault will eventually be related to the various peaks on the waveform, and the clutter without obvious engine fault is not easy to eliminate (which is correct in some cases), that is to say, when the individual peaks on the waveform have nothing to do with the engine fault, it is very unlikely to be eliminated in the repair. To sum up, the rule for judging clutter is: If it can be concluded that there is no vacuum leakage in the intake manifold, the contents of hydrocarbons (HC) and oxygen in the exhaust gas are normal, and the rotation or idle speed of the engine is relatively balanced, then clutter may be acceptable or normal.