- Misfire characteristics
- Possible causes of misfires
Cylinder transfer characteristics:
Cylinder transfer means that no (good) combustion takes place in a cylinder. This can be recognized by a shaking engine. When idling, the engine turns irregularly and when you give it gas, you hear a vibration in the engine. There is also a roaring sound at the rear of the exhaust. In this case, the car also has less power. In most cases, a warning light will illuminate on the dashboard.
Possible causes of misfires:
Cylinder overtopping is caused by poor or no combustion in the relevant cylinder. This can be caused by a defective ignition coil, a bad spark plug, an injector not injecting properly or when the compression is not right.
If a cylinder over-load fault has been stored in the computer (using cylinder 1) as an example, the cause of the problem can be searched for. Because cylinder overturning is often caused by a defective ignition coil (in an engine with a rod coil per cylinder), the ignition coils can be exchanged. Then exchange the ignition coil of cylinder 2 with cylinder 1, clear the fault and then see which fault returns. If the fault is now in cylinder 2, replace the ignition coil. If the fault remains in cylinder 1, then there is another cause. Then remove the spark plug. If it is completely black and wet with oil, there is a leak somewhere (possibly at the valve guides). If there is a strong smell of fuel, the fuel injector may be malfunctioning. If nothing else is visible on the spark plug, replace it with cylinder 2.
If the fault still remains with cylinder 1, then the problem is not with the ignition. In the case of indirectly injected engines with magnetic coil injectors, the injectors of cylinder 1 and 2 can then also be changed. This is not a good plan for direct injection engines, as the injectors are taught in the control unit. If the injector has possibly been changed and the fault has moved to cylinder 2, replace the injector.
If the fault is still present, it is wise to do a compression test to measure. A valve may not be sealing properly or there may be some other mechanical problem causing loss of compression. In that case, too much air leaks out, which means that proper combustion is not possible.