Q: Cylinder #4 misfire, PO304

为了确定您的问题是在数字4缸的注射器上进行的问题，就是要使燃油压力泄漏。如果打开钥匙和压力上升后燃油压力不会泄漏，请坐下。燃油压力应保持升高，并且最多每15分钟的psi不超过一个psi。如果您看到压力下降的速度很快，那么您的喷油器可能就是原因。如果有燃油栏，您将不得不封锁燃油栏的返回线，以确保不是燃油压力调节器进行泄漏。

If the injector is the suspect, replacing it will be the answer. If you do not have any pressure loss, you will need to do an injector driver test for the cylinder by hooking up a noid tester light to the injector connector and see if the light blinks while the engine is running. If the light stays on, then the engine control module has a shorted injector driver. If the light blinks then you know the injector circuit is okay. Afterwards, a compression test on the cylinder is necessary. You will most likely find out that the injector is leaking and flooding the cylinder out. Make sure to check the oil to make sure that it’s not getting over filled by fuel leaking into the cylinder. If you feel you need help diagnosing the problem then contact a qualified mechanic toassess your misfire并进行必要的维修以使您的汽车再次上车。