What is a gasoline pump for a car and how does it work
Content
A gasoline pump is an important part of a car, without which it is impossible to supply fuel to the engine cylinders and, naturally, ignite the air-fuel mixture to drive the piston group. Each motorist must understand how different components of the car work. This is necessary to understand what to do if the car does not want to start, or stalls while driving.
Where is the fuel pump located?
The location of the fuel pump depends on the car model. In the classic with a longitudinal engine, this mechanism can be installed near the crankshaft. Models with a transverse motor can be equipped with a mechanical pump that is installed in the area of the camshaft. This is a common position of mechanical modifications.
As for the electrical options that are used in injection vehicles, their design is more complex than that of the mechanical counterpart. During operation, such a pump makes a decent noise. In addition to noise and vibration, the electrical modification gets very hot.
For these reasons, engineers at most automakers have placed this mechanism directly in the fuel tank. Thanks to this, the operation of the fuel pump is practically inaudible and at the same time it is properly cooled.
Purpose and principle of operation of the fuel pump
The name of the device itself indicates its purpose. The pump pumps fuel from the tank to the carburetor or through the nozzles directly to the cylinders themselves. The principle of operation of the part does not depend on its size and model.
Every modern internal combustion engine is equipped with an electric gas pump. How does she work?
How does a gasoline pump work?
Electric models work on this principle. A signal is received from the on-board computer, and the pump starts pumping gas into the highway. If the engine does not start, the computer shuts off the device so that it does not burn out.
During the operation of the motor, the control unit monitors the throttle position and the fuel feed rate. The computer also changes the speed of the pump impeller to increase or decrease the volume of transported fuel.
What is an electric gas pump?
Gasoline pumps consist of:
- electric motor;
- hydraulic blower.
An electric motor is needed so that the fuel supply does not depend on the speed of rotation of the motor of the car, as in mechanical modifications.
The second unit consists of a safety valve (relieves excess pressure) and a check valve (prevents gasoline from returning to the tank).
Types of gasoline pumps and how they work
All fuel pumps are divided into two types:
- mechanical;
- electric.
Although the main task of the devices remains unchanged, they differ from each other by the principle of operation.
Mechanical type
This category of gasoline pumps is used on carburetor engines. They are installed in close proximity to the motor, as they are driven by rotation camshaft (on front-wheel drive cars, the camshaft is equipped with an eccentric that drives the pump lever pusher) or rotation of the oil pump drive (rear-wheel drive cars).
Such pumps have a simple design. Inside them is a spring-loaded membrane. In the center, it is attached to a rod abutting against the drive lever. In the upper part of the body are two valves. One works to bring gas into the chamber, the other to exit it. The amount of fuel supplied to the carburetor depends on the space above the pump diaphragm.
The camshaft eccentric (or in the case of rear-wheel drive auto cam of the oil pump drive) drives the pusher, which with the help of the lever changes the position of the diaphragm. When the eccentric moves, the diaphragm lowers and a vacuum is created in the pump tank. Due to this, the inlet valve is activated, and gasoline enters the chamber.
The next movement of the cam eccentric allows the spring-loaded membrane to return to its place. From this pressure is created in the chamber, and the fuel through the exhaust valve goes to the carburetor.
Electric fuel pump and their types
Electric gas pumps are installed on the injection type of engines. In this case, the fuel supply should occur under pressure, so mechanical models are useless here.
Such pumps can already be located in different parts of the fuel line, since they are already powered by electricity. Among all models, three main types are distinguished:
- roller;
- centrifugal;
- gear.
1) Rotary roller pumps are installed anywhere in the fuel line. They work on the principle of moving the rollers inside the supercharger. The rotor of the electric motor is located with a slight offset relative to the roller chamber of the supercharger.
When the rotor rotates, the roller shifts, which creates a vacuum in the cavity. Through the inlet valve, fuel enters the pump. As the roller moves, gas leaves the cavity through the exhaust valve.
2) Centrifugal models are always installed inside the gas tank. An impeller is installed on the electric motor shaft. It rotates inside the supercharger tank. From the speed of rotation of the blades creates turbulence of fuel in the chamber. Further, through the exhaust valve, gas enters the fuel line, where the necessary pressure is created.
3) This type of gasoline pump also works by rotating the shaft with an offset axis. A gear is mounted on the rotor, which is located inside the secondary gear. Fuel enters the part chamber through the movement of the gears.
Most cars have centrifugal pumps. They provide a more even supply of gasoline and are easy to manufacture.
The main malfunctions of the gasoline pump
Due to their simple design, electric pump models have a long working life. And mechanical practically do not break. Most often, the membrane, or the spring located under it, breaks down in them.
Here are the main malfunctions of gasoline pumps:
- Overheating of the electric motor due to frequent driving with a low fuel level in the tank.
- Contact oxidation, or wiring damage.
- Clogged filter.
- Depreciation of moving parts.
The serviceability of gasoline pumps is checked as follows.
- Mechanical. The top cover is removed and the state of the diaphragm is checked. To test it in action, you need to disconnect the hose from the carburetor and start the engine. If the jet is fed evenly and with a good pressure, then it works correctly.
- Electric. Their serviceability is checked even easier. When the car ignition is turned on (turning the key one position), the diagnostic lamps light up. At this point, the gas pump should start working. The driver should hear a soft buzz for 1-1,5 seconds. If this sound is not heard, then something happened to the pump.
Most often, breakdowns of fuel pumps are eliminated by their complete replacement. In case of failure of the membrane in mechanical models, it can be replaced with a new one by purchasing a gas pump repair kit in a store.
About how to put an electric fuel pump on a carburetor engine, see the video:
Service life of the fuel pump
The service life of a fuel pump depends on its design and the materials from which it is made. Depending on the model of the device, the fuel pump will work without interruptions in the interval from 100 to 200 thousand kilometers of the car.
The pump fails for two main reasons:
- untimely replacement of fuel filters. Moreover, some pay attention only to the fine cleaning element, but the cleanliness of the mesh, which is installed directly on the pump itself, deserves no less attention. When the pump tries to build up pressure through a dirty filter, it gets hotter. Timely maintenance will extend the pump life;
- the fuel tank is often low on fuel. Because of this, the device does not receive adequate cooling, so the risk of overheating increases significantly.
Also pay attention to the video on how you can restore some pumps:
Questions and answers:
How to check if the fuel pump is working? The operability of the mechanical fuel pump is indicated by the presence of gasoline in the fuel filter. The electric heat pump emits a barely audible buzz after turning on the ignition.
How are fuel pumps divided according to purpose? The low pressure pump is used in carburetor engines. The high pressure analogue is used in injection models. A distinction is also made between submersible and external pumps.
How to check a fuel pump at home? Check fuse, relay, battery charge and wiring integrity. The electrical part of the pump comes out less frequently. Often the reason is the wear and tear of its parts.
