Characteristics of a Broken Car Fuel Pump and How to Fix It


Lately, the fuel pump seems to be in the spotlight after a number of manufacturers such as Toyota, Daihatsu, Mitsubishi, and Nissan have recalled or recalled a number of models because of problems with this part.


So what exactly is a fuel pump and what does it do? In general, the function of the fuel pump in any type of motor vehicle, including cars and motorcycles, is actually only one, namely pumping fuel.


As is known, the gasoline in the storage tank will be pumped to flow into the combustion chamber and converted into energy that will help the vehicle engine start. However, different types of vehicles, different fuel flow process. In the following, automotive tips will provide a complete review regarding the definition of a fuel pump to the costs required to replace a damaged fuel pump.


What Is a Car Fuel Pump?


Simply put, the fuel pump is one of the components in the fuel supply system that determines the engine to work normally.


A faulty gas pump or better known as a fuel pump can cause the engine to break down or die suddenly. Therefore, many car owners ask how to detect when the fuel pump has a problem, because the presence of the device is not connected to the check engine indicator.


Although the problem with the fuel pump is a little difficult to identify, because all the indicator lights on the car dashboard will not show signs. But that doesn't mean it's impossible to detect it, it's a good idea to start recognizing the signs to be more comfortable and safe while driving.


Car Fuel Pump Function


The function of the fuel pump in a car is to pump fuel from the tank to the engine of a motorized vehicle. The fuel in the storage tank will be pumped into the combustion chamber.


In this combustion chamber, the fuel then turns into energy that can make the car engine live. Although it has the same function on all types of vehicles, the process of delivering fuel is different.


For example, in a vehicle engine that uses a carburetor, the flow process is that fuel flows from the tank to the carburetor. Therefore, the function of the fuel pump is to pump fuel from the tank to the carburetor.


Meanwhile, for vehicles with the injection type, the fuel flow process starts from the tank to the injector. So, the gas pump functions as a component that pumps fuel from the tank to the injector.


Types of Car Fuel Pumps Based on How They Work


In addition to the different fuel pumps based on the type of vehicle, these components are also differentiated based on how they work.


1. Mechanical Fuel Pump


A mechanical fuel pump is one type of fuel pump which still uses mechanical movement utilizing engine rotation. Mechanical fuel pumps utilize a diaphragm located in the center of the pump. Then there are two valves, namely the intake valve and exhaust valve. The way these two valves work opposite each other to regulate the flow of fuel. To move the diaphragm there is a pull rod connected to the rocker arm. This rocker arm will be connected to the camshaft. With this, the engine speed through the camshaft will be connected to the diaphragm via the rocker arm and pull rod. Mechanical fuel pumps are widely used in conventional fuel systems.


Advantages of mechanical fuel pump


  1. No battery or electricity required
  2. Easier maintenance

Disadvantages of mechanical fuel pump


  1. Noisy
  2. Bigger vibration

2. Electric Fuel Pump


An electric fuel pump is a type of fuel pump that utilizes electrical energy from a battery where the pump's performance is controlled by this electrical energy. This type of fuel pump is widely used in today's vehicles that already use EFI technology. Electric fuel pumps can produce greater pressure than mechanical fuel pumps of 2 Kg/cm2 or more.


Advantages of Electric Fuel Pump


  1. less vibration,
  2. Can be installed in any part, no need to connect to the machine directly,
  3. Can work even when the engine is off.

Disadvantages of Electric Fuel Pump


  1. Must use electricity/battery,
  2. As well as slightly more complicated maintenance.

Inside the electric pump there are several components such as a rotor which is a rotating component that functions to suck and suppress fuel. In addition, there are magnets and armatures that will make the pump work rotating. The working principle is the same as the starter motor, the difference is only in the utilization of the rotation generated by the motor.


Characteristics of a Damaged Car Fuel Pump


Considering the function of the fuel pump which is very crucial to the sustainability of the vehicle's performance, AutoFamily is obliged to care for and maintain its condition. Be careful and be aware if your car's fuel pump shows signs of damage with the following characteristics:


1. the Car Becomes Difficult to Start


The first characteristic is that the car engine will be difficult to start when parked for a long time. This is caused by the fuel that should be ready, but is not available in the fuel line or the so-called fuel line.


Not only that, when the car's gas pump starts having problems, the car engine crashes. This is because the gas pump is clogged with dirt from the gas tank due to poor fuel quality. So the engine feels empty even though the gas pedal has been stepped on.


2. Car Injection Indicator Light Flashes


Damage to the function of the fuel pump is often indicated by a car indicator light that keeps on burning. This injection indicator light is located on the injection component which is located on the dashboard inside the steering wheel. If there is a flickering on the check engine lamp, it is clear that there is a problem with the fuel pump of the car.


In addition to the two things above, there are also other characteristics of a damaged car fuel pump, such as a burnt gas pump fuse, which can be a sign of damage to this component. The cause of the burnt fuse is because it is clogged with dirt deposits, so the performance of the fuse is heavier. If the fuse is blown, then the performance of the gas pump is also not normal. And also the pungent smell of gasoline from exhaust fumes caused by the combustion process in the engine being less than perfect. Therefore, pay attention if there is a strong odor from car exhaust fumes.


How to Repair Car Fuel Pump


Fortunately, the damaged fuel pump can be repaired. How to repair a car's fuel pump consists of several steps, starting from the relay, wiring harness, to the resistance of the fuel pump. Here is the full explanation.


  • Fuel pump relay check

The fuel pump relay is a component that functions as an electronic switch to drain electric current so that the fuel pump can work. How to repair a car's fuel pump starts from this section. The trick, remove the relay from the socket. Then, check the resistance of terminals 3 and 5. Ideally, the standard result is 10 kilo Ohms or more. Continue to check the resistance of terminals 3 and 5 with the addition of one power at terminals 1 and 2. The standard result is below 1 Ohm.


  • Checking the fuel pump wiring harness

The fuel pump has an electrical circuit with a specific wiring diagram. This part must be checked in a series of ways to repair a car's fuel pump because it could experience an electrical short. The check flow is as follows:


  1. Check the connection between the FC1 terminal and the F/P relay. The standard result is below 1Ω.
  2. Check the connection between the FC1 terminal or the F/P relay with the body mass. Standard yield of 10 kΩ or more.
  3. Check the connection of the F/P relay terminal with the fuel pump. The standard yield is below 1.
  4. Checking the relation of terminal 3 of the pump motor to the mass of the body. The standard yield is 10 or more.
  5. Check the connection of terminal 4 of the pump motor with the mass of the body. Standard yield below 1 Ohm.
  • Check fuel pump resistance

The last way to repair a car's fuel pump is to check its resistance. It aims to determine the performance of the pump motor. If the resistance is too large, then the pump motor will spin slowly and cause various problems. For example, delays in fuel supply and reduced fuel pressure.


The check is carried out by disconnecting the fuel pump terminal, then measuring the resistance of terminals 3 and 4. The standard result is 0.2-0.3 Ohm at a temperature of 20 degrees Celsius. If there is a difference, it is necessary to replace the pump motor.


Maybe you are also starting to ask how to prevent gas stations from experiencing such problems? One way is by cleaning or draining the fuel tank regularly.


Not only that, you can also apply some other tips. There are some simple tips you can do to prevent problems at the car gas station. What are those? Here is the full explanation.


  • Don't be late for refueling

The first tip is that you shouldn't be late for refueling. This is because the fuel also has a function as a lubricant and coolant for gas pumps. So if there is no fuel, the gas pump will be hot and not working properly.


Car owners are advised to immediately refuel when the remaining fuel is only a quarter of the tank volume. This is to keep the gas pump always working properly to pump the fuel needs of the vehicle.


  • Draining the Tank Regularly

The second tip is to drain the fuel tank regularly. For new cars, drain the fuel tank at least after five years of use. This is certainly different from a car that has been used for a long time.


For old cars, at least do a fuel tank drain every two years. Draining the tank aims to clean the bacteria at the bottom of the tank and remove dirt on the tank due to dirty fuel.


  • Refueling at the Right Time

The last tip is to always refuel the car at the right time. What do you mean? The point is not to refuel when the gas station is filling the bunker or when the weather is cold.


This is because when the gas station fills the bunker or when the gas station is busy during the day, there is a possibility that the gas station bunker is not 100% sterile from the dirt that settles at the bottom of the bunker. So, it's best to fill up with fuel when the gas station is empty.


After knowing the function and characteristics of the problematic fuel pump, and it turns out that your car's gas pump is indeed problematic, then immediately take your car to the nearest authorized repair shop. There you can make repairs and replacements on the pump if needed.


Due to Damaged Car Fuel Pump


The case of a damaged fuel pump is mostly due to this component being clogged by dirt deposits. The dirt can come from many factors, including poor fuel quality. Or it could be due to the old fuel being allowed to settle in the tank due to the car never being run.