12 Volt Fuel Pumps
Automotive Fuel Pumps
A fuel pump is made up of many different parts, with the fuel tank making the most critical and noticeable ones. The tank can be found most of the time placed opposite to the end where the engine is placed. What is the function of the fuel pump? Its main job is to draw fuel from the tank so as to send it to the engine. There are two types of fuel pumps, the mechanical and the electronic one. The former is for carburetor-based cars and the second one for cars with an electronic fuel injection system the modern ones.
On the other hand, an electronic fuel pump delivers a thin mist of fuel into the combustion chamber. It uses a computer for monitoring and controlling the throttle position, the ratio of air and fuel and the exhaust contents. As this system doesn't use any existing force like vacuum for drawing the fuel through the lines, it is necessary that the fuel pump be placed at the source. So, the fuel pump would be found either within or next to the tank.
As the fuel pump is electronic, it would be powered electronically. At times, you can identify it from the soft and regular humming sound released from the rear part of the car. It is not unusual to find failure of the fuel pump, especially in cars having electronic fuel injection. Generally, when there is a failure, your car is going to splutter and die, and it wouldn't restart. And, the car would seem like it is out of gas. You can verify a fuel pump failure by looking at the end of the fuel delivery system. If you find that fuel is not reaching the engine, then there is a good chance that the pump has failed.
When the electronic fuel pump has broken down and it comes to replacement, you can consider getting help from a mechanic. There are different types of designs with different ways of accessing the fuel pump. One design gives you access from below the car. Another gives you access from within the car by removing an access panel. And, another design, the most channeling one, requires the fuel tank to be removed.
Even though the fuel pump is such an important component of your car, it would come as a surprise that most car owners don't ever realize that it is there unless it comes down to a breakdown. This part is very reliable and would continue pumping fuel for many years. The internal working of these pumps, especially the mechanical ones is relatively simple. The internal make consists of a rubber diaphragm fixed inside the housing and an actuator arm.
There are two types of fuel pumps puller and pusher pumps. The mechanical pumps come in the category of puller pumps. The powerful suction helps in pulling gas from the tank and into the engine. There is little distance between the pump and the carburetor. This means that there is no need for the puller pumps to work hard to maintain the fuel line pressure. On the other hand, the pusher pumps are designed to push the fuel through the line. Electric fuel pump has a pusher fuel pump and they are located near the tank.
There are dual stage pumps, which are also used to operate windshield wipers. In the older car models, the wipers were actuated with vacuum. But, when the vacuum pressure was reduced, the wipers used to stop. This problem was solved by the introduction of the dual stage pumps. The pump contains a fuel section working in the same way that the normal fuel pumps work. There is a vacuum booster section that is run through the rotational motion of the eccentric from the camshaft.
The suction helps in opening the intake valve inside the vacuum section. This results in air to flow in through the intake pipe. During the entire duration when the wipers are not being used, the diaphragm would be kept against the spring pressure with the help of the intake vacuum. So, the diaphragm is not going to move for each strong made by the pump arm. When the pressure created by the vacuum increases the fuel pump's suction, the air is going to flow out. In such a case, the vacuum section would become non-operative.