All diesel fuel injectors have return pipes, which is a well-known thing. Because the oil return volume of in-line mechanical pump is small and the working pressure is not high, even if the return pipe is slightly blocked, there is no big problem.
In the era of the Three Kingdoms and four kingdoms, high-pressure common rail electronic control injection has played a leading role. It is very important to ensure that the diesel oil circuit is clean. If the diesel oil circuit is not clean and there are impurities, even if the return pipe is blocked, the injector will damage the solenoid valve due to poor oil return. An injector costs thousands of yuan at every turn. Such a loss is unbearable for our truck drivers.
Forum card friend “hope103” replaced three new parts after the fuel injector was stuck. After the new parts were replaced, the old problems were solved, but the new problems came. When the new fuel injector is replaced and the engine is started, the fuel injector of cylinder 1 is washed away from the solenoid valve into two sections, and the fuel injector is directly scrapped. It is still the case when three fuel injectors are replaced.
Card friends were puzzled and asked for help from the forum card friends “Jij truck” SongGe. SongGe judged that the fault was caused by the blockage of the oil return pipe, because the oil return volume of the high-pressure common rail electronically controlled diesel engine is very large, and the engine with large displacement can reach up to 400 liters per hour. If the oil return volume is not smooth, the fuel injector must be choked.
According to this idea, kayou checked the oil return circuit and found the cause on the hollow bolt of the oil return pipe. The hollow bolt is blocked. The analysis should be that in the process of replacing the fuel injector, impurities fell into the oil return circuit, resulting in blockage, resulting in the fuel injector being washed away. After replacing the hollow bolt, the fault was eliminated.
The high-pressure common rail system has high pressure and high precision of accessories. Slightly larger impurities entering the fuel supply system will cause damage to the fuel injector. Unfortunately, the same problem caused two failures. It is important to ensure that the fuel of the common rail system is clean, especially during maintenance, to avoid impurities entering the oil passage. In addition, when replacing the diesel filter, you must not replace the fake or national grade 2 filter. The temporary cheapness will bring greater losses.
Small problems can lead to major faults. The high-pressure common rail injection system has high requirements for diesel cleanliness due to its high precision. It is a common saying that when replacing the high-pressure common rail diesel filter, we must use the qualified products of the factory to ensure the normal operation of the common rail system and avoid economic losses caused by unnecessary damage.
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