Electric Fuel Pumps - Design, Work And Faults

May 10, 2018 by Kornum Burnham

Electric fuel pump is utilized in modern internal combustion engines to provide fuel in the fuel tank to the injectors. The pump must provide fuel under high pressure, so that the nozzle can spray it in the engine. For the proper engine performance fuel pressure must be within allowed specifications for a given engine. Too much stress causes uneven engine running too rich mix, and excessive pollution.

Electric fuel pumps are usually installed in fuel tank (ingestion), even though some can be installed outside. Some automobiles can be equipped with two pumps (one pump in the tank and the main pump on the exterior). The positioning of this pump in the fuel tank helps permeate the buzzing sound of pump’s electric engine. Submersion to the gas helps lubricate and cool the pump engine. Driving with gasoline tank full of over 14 of its quantity can shorten the life span of the pump and trigger rapid overheating. It also increases risk of pump left with no gasoline through rapid acceleration or deceleration.

The pump is usually part of a module which also comprises a float which carries electrical signals to the level index, located on the dashboard. If the gas pump needs replacing, it may be replaced separately or the complete module assembly (it is expensive, but much simpler).

Different electrical fuel pumps have different designs. This type of pump can create very high pressure and continuous flow. But in the outlet of the gas pump was strong pressure changes, so frequently from the gasoline after the pump was installed damper to decrease the amplitude of pulsation of gas pressure. Circulating room may also be set up away from the tank and utilized with the second low-pressure pump installed at the fuel tank.

There is another form of gas pump - out “rotor-type”. This design is similar to layout of the oil pump and uses the offset rotor to push the gas through the pump. Another variant of the roller pump - “vane-type”. The blades are used instead of rollers to push the gas throughout the pump. Most modern cars use a pump turbine. Blades of the impeller push gas through the pump. Turbine type pumps don’t produce the pressure fluctuations these types are less complex to fabricate and more reliable in operation. It is likely to substitute a gas pump by not first unit. In this case gas pump’s output should be within initial specifications and as consumption the same as the first one. Use of an improper specs can cause corrosion of performance of the car.

How can electrical fuel pump work?

After the ignition, the digital control unit excites the relay, which provides voltage to fuel pump, its engine begins to rotate, and within a few seconds it creates necessary gas strain. Fuel feeds to the inlet pump through a mesh filter to postpone the rust and dirt. Outlet of this pump the gas passes through the check valve, single acting (valve maintains a residual pressure in the system, when pump does not work) and feeds to the engine through the fuel line and filter.

Further, the gas enters the gas rail, based on the motor and out of the railing to each injector. ремонт на дизелови дюзи , located on the ramp, keeps the gas pressure and throws any extra back to the tank. Start the motor and the electrical fuel pump begins to operate continuously and also to keep pumping gas before the engine is operating. If the motor stops, then the digital control device receives a signal from the sensor and the crankshaft ECU will switch off the pump.