Recently, a kayou who ran the Tibet route found that the fuel consumption of his car was higher than before, and the power also decreased. The car of the card friend is Jiefang J6 tractor. It has driven 400000 kilometers in more than two years. It has been using genuine filter elements to refuel at regular gas stations. Kayou is going to go to SongGe, Qingxian County for inspection. Xiaobian and his colleagues decide to go together to see what causes the abnormal fuel consumption.
After asking about the basic situation of the vehicle, SongGe connects the diagnostic instrument with the vehicle and checks the data flow of the vehicle to determine where the problem is. After checking the data flow, it is found that the trigger current of the fuel metering unit valve is abnormal. The vehicle is 1360 Ma, and the normal value should be more than 1400 ma.
It is preliminarily judged that the fuel metering unit may be worn, resulting in abnormal current. It is decided to disassemble the metering unit to see if it is worn internally. After disassembling the fuel metering unit, it was found that the valve core of the metering unit was seriously worn.
There are also impurities on the hollow screw filter screen on the oil pump. The impurities look a little like aluminum foam. Replace the fuel metering unit with a new one. After cleaning the hollow screw, check whether the vehicle data flow is normal.
After replacing the new metering unit, the fuel trigger current increased slightly, and the current still did not reach 1400ma. SongGe judged that the fuel injector valve assembly was worn, resulting in a large amount of fuel return, and the trigger current of the fuel metering valve did not rise. He decided to disassemble the fuel injector for inspection.
After disassembling the fuel injector, it is found that the fuel injector valve assembly is slightly worn. Only this little wear will lead to abnormal fuel consumption of the vehicle. As other parts of the fuel injector are in good condition, the fuel injector can be repaired by replacing the valve assembly. The valve components replaced this time are original Bosch accessories. In this small series, I remind card friends that when repairing the fuel injector, we must choose original Bosch accessories. Fake accessories are only usable, and the service life can not be guaranteed.
Fuel injector repair fuel injector is a meticulous work. All parts are very small and can be clamped with tweezers. The fuel injector shall be assembled in a constant temperature environment to avoid the impact of temperature difference on the assembly accuracy of fuel injector.
The injector with new valve assembly shall be inspected on the testing equipment. After testing, all six repaired injectors pass the test.
The process of installing the fuel injector is emphasized here. First install the fuel injector in place and fix the fuel injector position with a pressing plate, but do not tighten the screws. Then install the crossover pipe. After the crossover pipe is connected with the fuel injector, tighten the fixing screws of the crossover pipe, and finally tighten the screws of the fuel injector pressing plate. This installation can ensure that the jumper pipe is well connected with the fuel injector, so as to avoid oil leakage and pressure relief.
After all the fuel injectors are installed, start the vehicle to test the data. After the test, the current of the metering unit recovers to more than 1400ma. The trigger current of the metering unit should not be viewed simply for the maintenance of the injector, but should be viewed comprehensively from multiple parameters, such as inlet pressure, duty cycle of the metering valve, etc.
Many friends and Xiaobian have the same question. The car has been using genuine filter elements. Why is there wear of fuel injectors? I learned from the chat that the fuel tank of the card friend has been modified to heat the fuel tank, and the modification factory has cut the fuel tank when installing the heater. Xiaobian guessed that the aluminum foam during modification was not cleaned up, and the aluminum foam entered the fuel system with the fuel.
When cleaning Parker filter element, we found a large amount of aluminum foam at the bottom of Parker filter cup, which confirmed our conjecture. Just imagine, if you don’t use the genuine filter element, more aluminum foam will enter the fuel system with diesel. It’s not as simple as replacing the valve components today. The low-pressure oil pump and high-pressure oil pump may be damaged, and the consequences will be more serious. Although kayou uses an authentic filter element, the filter element can only filter out aluminum foam greater than 4 microns, and those less than 4 microns still enter the fuel injector, resulting in the wear of the valve components of the fuel injector, resulting in high fuel consumption and insufficient power. Aluminum foam is the culprit behind the damage of the fuel injector.
After seeing the aluminum foam, the friend shouted regret. Because Parker was installed inside the girder and could not see the bottom of the filter cup, kayou neglected to check it every day. If the aluminum foam can be found and cleaned in time, the service time of diesel filter element will be shortened and the fuel injector will not be worn.
In the daily chat with friends, I learned that there are many people who have caused fuel injector damage due to aluminum foam. So how did the aluminum foam come from? Xiaobian thinks there are two reasons:
First, refitting the fuel tank for heating: when refitting the fuel tank for heating, the aluminum foam generated by cutting the fuel tank was not cleaned up, and the aluminum foam entered the diesel, resulting in damage to the fuel injector.
The second is the opening welding of the partition plate inside the fuel tank: the opening welding of the partition plate is loose, the vehicle running diesel hits the partition plate, the friction between the partition plate and the fuel tank generates aluminum foam, which enters the fuel system with the fuel.
Xiaobian reminds you that when refitting the fuel tank, you should clean the aluminum foam in time and shorten the service time of the diesel filter element. Friends who have not modified the fuel tank heating, if aluminum foam also appears in your diesel filter cup, it is likely that your fuel tank diaphragm has been welded. The diaphragm should be welded firmly as soon as possible, and a new diesel filter element should be replaced in time to avoid greater losses.
Fuel injector, as the core component of EFI vehicle, is distressed by the high maintenance cost if it is not properly maintained. Although the card friends in the article use genuine filter elements, they lack daily inspection and still fail to resist the damage of aluminum foam to the fuel injector. Xiaobian reminds you that while using genuine filter elements, you should also strengthen the daily inspection of vehicles and deal with abnormalities in time to avoid unnecessary losses.
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