Fuel pumps are a necessary part of a car. The job of a fuel pump is to draw fuel from the fuel tank through a pipe and then inject the gas into the carburetor.
As the fuel pump feeds the carburetor fuel, the engine sucks in the mixture of fuel and filtered air and produces motion.
Can a bad fuel pump cause bad gas mileage?
A faulty fuel pump can cause reduced gas mileage. The purpose of a fuel pump is to feed the carburetor with fuel. The engine sucks in the mixture of fuel and air. If the fuel pump sends too much gas to the carburetor due to it being defective, you will notice a decline in gas mileage.
A fuel pump provides fuel to the carburetor by drawing gas from the fuel container through a pipe. As the fuel pump supplies gas to the carburetor, the carburetor provides the engine with fresh air and fuel. The engine sucks in the mixture of fuel and air.
There are two types of fuel pumps. One type of fuel pump is electric and the other type of fuel pump is mechanical. Both types of fuel pumps are the same in terms of purpose but function differently and are located at different parts of the car.
Mechanical fuel pumps are located beside the car engine because they are connected to the camshaft. The camshaft is a type of shaft driven by the crankshaft connected to the car engine.
Unlike mechanical fuel pumps, electrical fuel pumps are not driven by the camshaft. Therefore, they are sometimes located near or inside the fuel tank. Electrical fuel pumps use current from the car battery to provide fuel to the carburetor.
Nowadays, cars are more efficient than cars manufactured earlier. The carburetor allows fuel to flow inside only when it needs the gas. When the gas is not required, it remains in the pipe till it is allowed inside the carburetor.
Therefore, the fuel pump is the only device responsible for delivering fuel to the carburetor. A defective carburetor will cause poor gas mileage. It will affect the overall gas mileage of the car.
How does a bad fuel pump affect gas mileage?
Fuel pumps are a vital part of the car. They play a prominent role in driving the car engine. Without a fuel pump, the car engine will not receive any fuel to produce the driving force.
Therefore, a bad fuel pump will harm your car and the gas mileage. It will cause issues in the performance of the vehicle and its drivability.
If the fuel pump is defective, your car may not even start. The cylinders in the car engine will not have enough fuel to fire up. The incorrect ratio of gas to air will not let your car start.
Moreover, a failing fuel pump will supply the carburetor with excessive fuel when it opens to allow gas in it. Excessive supply will significantly decrease the gas mileage of the car. You will see a rapid decline in your car’s gas mileage.
What are the symptoms of a bad fuel pump?
Other than a decline in gas mileage, other symptoms indicate that your fuel pump has gone out. Below are the signs to look out for:
Overheating engine:
If your car has a mechanical fuel pump, the fuel pump is probably near the car engine. When a fuel pump starts to fail, it overheats. So, the overheating fuel pump will cause the engine to overheat.
If you notice that your car engine is overheating, you should stop the vehicle as soon as possible.
Power loss:
If you notice that your engine is losing power, the fuel pump may be failing. Loss of engine power will be most noticeable if you are driving up a steep slope and your car stalls.
If your car stalls or cannot reach the higher ground, the fuel pump is probably not being able to supply the fuel required.
Stalled engine:
You can experience a stalled engine if the fuel pump is failing. If the fuel pump fails to deliver enough fuel, your car will not start. Moreover, the car engine may not also work due to the clogging of the fuel pump of fuel lines.
These are some of the common symptoms which can help you identify a failing fuel pump. If you feel like you may have a defective fuel pump, check for the above signs.
What happens when fuel pump goes out while driving?
Below are what might happen if the fuel pump goes out while driving:
Engine stops:
If the fuel pump goes out while driving, the engine will stop working. As a result, you will feel your car slowing down. Eventually, as the engine does not receive fuel to run, the vehicle will come to a stop.
Power loss:
If you feel like your car is losing power, the fuel pump is probably out. You will feel that your vehicle is slowing down.
If you are climbing a steep slope, the car will lose significant power. As a result, you will not be able to get to the top.
Overheating engine:
A defective fuel pump will overheat and cause its surroundings to overheat. If the car engine is close to the fuel pump, the engine will overheat.
You may see the engine overheat light shine on the dashboard. If you see that sign, pull over the car.
You may face these issues if the fuel pump goes out while driving.
How long can you drive with a bad fuel pump?
If you are driving with a bad fuel pump, you can expect the car to turn off after about 20-30 minutes of driving. The vehicle will abruptly stop and probably will not start when you turn the keys to start the car.
Furthermore, you may be able to drive till the engine gets too hot. You can let the engine cool down to surrounding temperatures. However, if the same thing repeats, it is a sign the car’s fuel pump is going out.
What makes a fuel pump go bad?
These are some of the causes why a fuel pump goes bad:
Electrical fault:
If the battery fails, the fuel pump will not receive sufficient power to function.
Moreover, blowing of the fuse of the fuel pump for some reason will disconnect the battery will be disconnected from the fuel pump This will not allow the battery to supply power to the fuel pump.
Wear out:
A fuel pump may go out if it is used for a long time. Due to old age, it may go out. In such a case, replacing the fuel pump will solve the problem.
Fuel contaminants:
Sometimes, the fuel may contain some harmful contaminants. Contaminants may be dirt, moisture, or problematic compounds. These can effectively reduce the lifetime of a fuel pump.
Rusting and failing of fuel filter:
Fuel containers may begin to wear. Plastic fuel containers break down, and steel fuel containers rust. Also, the fuel filter starts to clog up and fails to stop debris from entering the fuel pump.
The above reasons can cause a fuel pump to go out. If you want your fuel pump to stay effective for a long time, make sure these do not happen.
How long does a fuel pump last?
As mentioned earlier, fuel pumps play a significant role in a car. They help provide the engine with the necessary amount of fuel. Without the fuel pump, the car would not even start.
Since fuel pumps are necessary, they are manufactured to live the car’s lifetime. It is estimated that fuel pumps can go more than 200,000 miles. Most cars are refurbished after traveling 200,000 miles.
Car experts say that after 100,000 miles, the fuel pump may start failing if a surrounding part is changed. So, if the carburetor was replaced with a new unit, the fuel pump may fail. If no parts were changed, the fuel pump will live a long life if you take great care of it.
Final Thoughts
Fuel pumps play a significant role in automobiles. Therefore, a failing fuel pump will cause a decline in gas mileage. Moreover, if the fuel pump fails to provide the required fuel, the engine may lose power. So, you should regularly check the fuel pressure and ensure the fuel filter is clean.
I am an automotive enthusiast and have been interested in cars since I was a little kid. I have worked in the automotive industry for many years and have extensive knowledge of vehicles and their engines. I am a father of two and I love spending time with my family.
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