Guide

Fuel Pumps

The fuel pump is a key component of the fuel system in both gasoline and diesel engines, supplying a certain amount of fuel under pressure to the injectors (in fuel injection engines) or the carburetor (in carbureted engines). Depending on the type of drive, there are mechanical and electric fuel pumps. An electric fuel pump consists of an electric drive (electric motor) and the pumping part (the pump itself) inside a metal casing. All parts of the fuel pump are in contact with the fuel. Gasoline has a high electrical resistance (over 1 megaohm), which prevents short circuits. The fuel pump is designed as a module, which includes, in addition to the pump, a fuel flow sensor, fuel filter, and fuel inlet line. Mechanical diaphragm pumps are pumps based on the movement of diaphragms, which, in conjunction with appropriate valves at the inlet and outlet of the pump, enable the creation of a suction effect on the suction side and pumping on the delivery side of the pump.

Where is the Fuel Pump Located?

The location of the fuel pump in a car can vary depending on the model and make of the vehicle. Generally, the fuel pump is usually located in the fuel tank. This is a popular placement due to several benefits, including:

• Cooling: The fuel acts as a natural coolant, helping to maintain the proper temperature of the fuel pump.
• Pressure: Placing the fuel pump in the tank allows for easier maintenance of the right fuel pressure throughout the system.
• Safety: Locating the fuel pump inside the tank can increase safety, as the fuel can be stored inside the tank rather than near the engine or other parts that can generate heat or sparks.

To access the fuel pump, it usually requires dismantling the rear or front part of the fuel tank. This is a task that often requires special tools and knowledge, so many people choose to entrust this activity to a professional mechanic.

In some vehicles, especially older ones, the fuel pump may be located outside the tank, usually near the rear axle or under the floor of the vehicle. However, in most modern vehicles, it is placed inside the fuel tank.

Symptoms of a Damaged Fuel Pump

Damage to the fuel pump can manifest in various symptoms, depending on the degree of damage and the type of car. Here are some common symptoms that can indicate problems with the fuel pump:

• Difficulty starting the engine: A damaged fuel pump can cause difficulty in starting the engine, especially when the car has been standing for a long time or in cold weather.
• Power loss: If the fuel pump is not delivering enough fuel to the engine, it can lead to a loss of power in the vehicle during driving.
• Noises from the rear of the vehicle: Sometimes, a damaged fuel pump can produce characteristic sounds, such as humming or buzzing, which can be heard from the back of the vehicle, especially when the key is turned to the “ON” position (without starting the engine).
• Engine stalling while driving: If the fuel pump is faulty, it can lead to the engine suddenly stalling during driving, especially during acceleration.
• Uneven engine operation: A damaged fuel pump can cause uneven engine operation or jerking during driving.
• On-board computer errors: In some cases, the on-board computer may register errors related to the fuel system, which can indicate problems with the fuel pump.

If you experience any of these symptoms, it’s a good idea to consult a mechanic or vehicle specialist to accurately diagnose the problem and take appropriate repair steps.

How to Check the Fuel Pump?

Checking the fuel pump can be complicated, but there are several diagnostic methods that can help determine whether the pump is functioning properly or not. Here are a few steps you can take to check the fuel pump:

• Check the fuel pump with a pressure gauge: A mechanic can connect a pressure gauge to the fuel system to measure the fuel pressure. If the pressure is too low, it may indicate problems with the fuel pump.
• Check the electrical supply: Check the electrical supply to the fuel pump. You can do this using a multimeter to ensure that the pump is receiving the appropriate electrical power. A lack of power may indicate a problem with the fuse, relay, or wiring.
• Check the sound of the pump: When the key is turned to the “ON” position (without starting the engine), you should be able to hear the operation of the fuel pump for a few seconds. If you don’t hear any sound, it may indicate a problem with the pump or power supply.
• Check if the fuel pump delivers fuel: This is a more advanced method that requires direct access to the fuel pump. You can disconnect the fuel hose before the pump and ask someone to turn the key to the “ON” position, while you check if the pump actually delivers fuel.
• Computer diagnostics: In some modern vehicles, it is possible to check the operation of the fuel pump using computer diagnostics. The on-board computer may display errors related to the fuel system, which can indicate problems with

If you suspect that the fuel pump is damaged but are not sure how to check it, it’s best to consult with an experienced car mechanic. A professional will be able to conduct more advanced tests and help diagnose the problem.

How to Start a Car with a Broken Fuel Pump?

It’s best not to try this at all. Starting a car with a damaged fuel pump can be difficult or even impossible, depending on the extent of the damage to the pump and the type of fuel system in the vehicle.

If the fuel pump is only partially damaged, there is a chance that the car might be able to start and move, but this might be more difficult or other engine operation problems might arise.

Some older cars with fuel injection may be started in emergency mode or with a backup fuel source in case of a fuel pump failure. However, in most modern vehicles, especially those with fuel injection systems, the likelihood of starting a car without a functional fuel pump is small.

Even if you manage to start the engine with a damaged fuel pump, there is a risk of further damaging the engine due to an insufficient amount of fuel, which can lead to other problems. The risk of potential consequences should deter a driver from attempting to start a car with a damaged fuel pump. A damaged fuel pump can cause uneven fuel delivery to the engine, leading to insufficient fuel in the engine, and in extreme cases, even to the engine stalling while driving.

If you suspect that the fuel pump in your car is damaged, it’s recommended to consult with an experienced car mechanic. Regardless of whether you try to start the car with a damaged fuel pump or not, it’s best to repair or replace the pump as soon as possible to avoid more serious problems related to the fuel system and engine.