EFI fuel pump principle and method for determining failure

click:518 2023/4/20

EFI fuel pump fuel pump by the pump, permanent magnet motor and the shell composed of three parts .
The working principle is : the permanent magnet motor driven pump powered rotary fuel oil from the suction inlet , flows through the electric fuel pump inside , and from the oil port pushed out to the fuel supply system . EFI fuel pump casing at both ends of curling clench , so that all components of an assembly is not removable , so the electric fuel pump is generally not repaired. Additional functions performed by the fuel pump valve and the check valve is completed, the role of a safety valve to avoid blocking the fuel line , the pressure rise caused by excessive damage to the fuel pump or pipeline rupture phenomenon . The calibration pressure of the safety valve 2.6bar, the check valve is provided to prevent the fuel pump stops working when the seal passage , the fuel system to maintain a residual pressure , so that the next time the engine starting easy. Bottom electric fuel pump is mounted on the inside of the vehicle 's fuel tank , oil tank has a partial subsidence formed on the tank bottom shell . Suction from a pool of oil , the oil pipeline through the mouth after connecting with an external fuel tank cap when the pump piping work . The upper part of the pump by the fuel tank cap and fuel tank cap gasket, oil pump pressure in the tank tightly . There is oil in the oil pump , oil return standard gauge arrow , press the arrow to determine the link pipe . Link pump circuit : pump circuit has 5-way connector , 2 -way power for the pump , and the other 3-way as liquid display . Red power circuit is " +" pole, the pole should be connected to the EFI system wiring harness , relay controls the power supply controlled by the ECU . The fuel pump provides fuel flow 80L / h , excess oil recirculation flow into the fuel tank , the fuel injection nozzle and the cooling body wash during the cycle .
Electric fuel pump is good or bad judgment :. A former electric fuel pump damage , which significantly increases the noise than the normal time, by listening to the sound can be judged. b. detecting electric fuel pump armature winding resistance , the general resistance of about 10 ~ 20Ω, if the resistance is too large or too small , indicating that the electric fuel pump armature winding short circuit, poor contact or brush around the blocked road other faults. c Check the electric fuel pump oil volume : Remove the electric fuel pump outlet pipe , the electric fuel pump through the terminal voltage above 11.5V , dosage cup to collect fuel from the oil port within 30 seconds of fuel pump should be less than 0.6 liters , otherwise described as a safety valve is faulty pump .
Electric fuel pump is irreparable pieces , when it is determined damaged and must be replaced. When the electric fuel pump removal and installation of the required total power must be cut off . Computer-controlled fuel pump features: When the fuel pump is turned on , connected to the ignition switch Ⅱ file location , fuel pump start , if ECU receives engine speed signal within 10 seconds is less than the minimum starting speed or when the engine is stopped , the pump power is cut off , the long-term aim is to prevent the pump work , and when unforeseen circumstances cut off the oil . When the engine is running or starting power conditions , the pump power is turned on .