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Activation and presentation of electric fuel pumps for motors
November 09, 2010 20:40 phoenix bus [ ]
The role of the fuel pump is to transport fuel stored in fuel tanks to the fuel pipeline of the jet. Fuel pumps in the earlier engine fuel system were mostly mechanical and are now replaced by electric fuel pumps. In addition, some of the electric fuel pumps that had been installed outside the fuel tanks had been placed in the tanks, taking into account heat dispersion, sound insulation and air resistance。
Fuel pump total
The role of the fuel pump is to transport the fuel stored in the fuel tank to the fuel pipeline of the jet. Fuel pumps in the earlier engine fuel system were mostly mechanical and are now replaced by electric fuel pumps. In addition, some of the electric fuel pumps that had been installed outside the fuel tanks had been built into the fuel tanks, taking into account the heat dispersion, soundproofing and air resistance. The fuel pump was installed in the tank and integrated with the fuel meter measurement unit。
Fuel pump metering component
The work of the electric fuel pumps is the same as that of the electric pumps, using electric power-driven and corresponding pumps, thus transmitting fuel to the fuel system. It is important to know that the fuel system must maintain some pressure in order to ensure that the fuel sprayed by the jets is more incisive and burning. However, when the engine goes out of fire, the pressure on the fuel system is lost and, in the absence of residual pressure, air resistance is easily generated within the pipeline at high temperatures. This makes it difficult to start the engine when the engine is restarted because the fuel system is in the air and it is difficult to ensure sufficient fuel. For this purpose, one-way valves have been installed in fuel pumps. Thus, when the fuel pump is out of operation, the one-way valve is closed to maintain residual pressure in the fuel pipeline and to facilitate the re-starting of the engine. Moreover, it is not clear whether you have noticed that when your vehicle has been parked for a long time, and if it is quiet inside, when you turn on the ignition switch without rushing to start the engine, you hear the sound of a “mucking” in the back of the vehicle. This was not a failure, but rather to ensure that the fuel system had enough pressure to start the engine, allowing the electric fuel pump to operate two to three seconds in advance. Safety valves have also been designed to prevent excessive pressure on the outlet side of electric fuel pumps, so that once fuel pumps are overstretched, the safety valves will be opened and the overstretched fuel will flow back into fuel tanks。
Fuel pump and engine control computer module
We mentioned earlier the saddle-shaped fuel tanks that were equipped in some rear-wheel-drive cars and vehicles such as suvs, which were divided into main and sub-oil tanks, but generally only an electric fuel pump was installed in the main tank. So how did the fuel from the sub-tank get to the main fuel tank? Using the iris principle, the engineers were able to extract fuel from the sub-fuel tank through the pipeline and to transfer it to the main fuel tank。
Examples of fuel system failures
In 2003, when the vehicle came to 1. 8 sedans, the user indicated that when the hot car went out of fire and re-started, the engine was difficult to start and the motor needed to operate continuously。
Pipes and lines above fuel pumps
Following the take-over, the test vehicle found that if it re-started as soon as the engine went out of fire, it would be perfectly normal and would become difficult to start again after a period of parking. Based on the symptoms of the vehicle's failure, we first tested the engine control system with the fail detector. Based on the results of the above-mentioned tests, it is possible to make a preliminary determination that the engine control system is not in question and therefore to focus the inspection on the fuel system. The pressure on the fuel system was therefore measured by the connection of the pressure gauge, and the observed fuel system worked normally when the engine was running. Considering that the failure of the vehicle occurred only after a certain period of parking, it is likely that the problem arises from the residual pressure of the fuel system, i. E., the leakage of the fuel system, which resulted in the system not being properly protected. The pressure on the fuel system of the vehicle was observed to be too fast after long periods of observation of the connection to the pressure gauge. The one-way valve of the fuel pump was ultimately determined to be damaged, resulting in the system not being properly protected。
Since one-way valves cannot be replaced alone, failure is eliminated after fuel pumps are replaced.
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