As you probably know if you have read our blog, a car engine is the true heart of the car that burns a mixture of petrol and air. The petrol is pumped along a pipe from the tank and mixed with air, from where the engine sucks in the mixture and produces energy.
The fuel injection system that is used on some engines makes the petrol and air get mixed in the inlet manifold. Here, an engine fuel pump draws petrol out of the tank. The pump can be mechanical and worked by the engine (something we saw mostly in the past), or electric, in which case it is next to the fuel tank or even inside it.
Types of fuel pumps and how do they work
As we said above, a fuel pump is the part of the car that supplies fuel from the fuel container to the carburetor of an engine. Since fuel supply is important to keep the engine running, a fuel pump is of big importance in every vehicle.
There are two significant types of fuel pumps: mechanical and electrical. Most vehicles operate with electrical fuel pumps nowadays, and mechanical fuel pumps are already a thing of the past.
How does a mechanical fuel pump work?
A mechanical fuel pump was a standard in the past, with vehicles that had a carburetor. The system moved fuel from the fuel tank to the carburetor bowl, driven by the eccentricity of the engine’s camshaft. It is located on the side of the in-line cylinder block engine.
The plunger and diaphragm pumps are among the most commonly used fuel pumps, whereas the diaphragm pump is a famous positive displacement pump. The pump contains a chamber in which volume increases or decreases due to the deflection of the flexible membrane. A mechanical fuel pump drives through a camshaft or a specific shaft that rotates, going under the pivot level and pushing the shaft up at one end. Gasoline cannot be returned from the 1st check valve, so it drains into the carburetor through another valve.
How does an electric fuel pump work?
Electric fuel pumps are a modern solution that revolutionized cars in many ways. They operate with an electric motor that rotates for some time to increase the fuel system pressure. There is also a Powertrain Control Module (PCM) timer that limits the amount of time in which the pump operates before the engine starts.
Once the fuel is pulled by the suction valve, it leaves the pump by a check valve, which sustains the residual pressure inside the engine. Fuel is forced to the engine through a pipeline and filter. The filter catches dust, rust, and other solid debris that may have to go through the pump, removing any contaminations to prevent the fuel injector from blockage.
How to keep your car fuel tank safe?
Your car’s petrol tank is placed at the opposite end of the car from the engine. Inside it, there is a float that operates an electrical sender unit that transmits current to the fuel gauge. This gives signals on how much petrol is actually in the tank. There is also an air vent in the tank, which is often a pipe or a small hole in the filler cap that allows air in as the tank gets empty. Some of the latest car makes and models have a carbon filter that traps fuel fumes in and prevents them from escaping.
Also, drivers should know that operating a vehicle with less than 0.25 fuel inside their tank will overheat the fuel tank and reduce the pump life. This can increase accelerating, braking, and sharp turns that may also increase the risk of temporary starvation of the pumps for fuel. Such exhaust gases may lead to improper lubrication and cooling of the electric fuel pumps and can damage the pump.