What happens if The Fuel Pump Goes Bad?

The fuel pump is an important part of an internal combustion engine because it supplies a sufficient amount of fuel for the combustion process of the engine. But sometimes the fuel pump gets damaged. However, there are a number of reasons why it may fail, and you may experience a number of symptoms associated with a bad fuel pump.

Let us go into detail on the symptoms of a bad fuel pump and other important aspects that will help you diagnose a bad fuel pump.

What Is A Fuel Pump?

In vehicles, a fuel pump is an electronic or mechanical component that delivers liquid fuel from the common rail to fuel injectors at high pressure in order to make the fuel more flammable in the internal combustion chamber of the engine.

Often, diesel vehicles have a fuel pump located near the engine that draws fuel from the fuel tank through a vacuum and delivers fuel at high pressure to the fuel injectors. The main purpose of the fuel pump is to send fuel with high pressure from the fuel tank to the fuel injector. But in some vehicles, the fuel pump is mounted in the fuel tank.

What happens if The Fuel Pump Goes Bad?

If a vehicle’s fuel pump goes bad, you will experience several symptoms. Such as difficulty starting the engine, noise from the fuel tank, hesitant acceleration, rough engine running, low fuel efficiency, smell of unburned fuel, engine stalling, or engine RPM not going up.

Let us know the symptoms of a bad fuel pump in detail so that you do not get confused about its symptoms.

1. Engine Not Starting

If the engine of your vehicle is not starting, this symptom can be caused by bad fuel. A bad fuel pump is not supplying fuel to start your vehicle’s engine. So the fuel pump should be checked when the engine won’t start.

However, there can be many other reasons for the engine not starting. such as a blocked fuel filter, a clogged fuel injector, an electrical fault or a mechanical fault.

2. Rumbling Noise From Fuel Tank

Often, in vehicles with a faulty fuel pump, a rattling sound can be heard from under the fuel tank or back seat. because there is an electric motor in the fuel pump. which sends the fuel under pressure to the fuel injector.

The motor of the fuel pump starts making a loud noise when it rotates due to damage. Even if the engine of your vehicle is running, the fuel pump still makes a sound. If these symptoms appear, the fuel pump must be checked.

3. Hesitation Acceleration

A bad fuel pump can cause a vehicle to hesitate during acceleration. because more fuel is required during acceleration. But the fuel pump is unable to supply fuel according to the acceleration of the fuel injectors in the engine. Due to this, the vehicle starts having problems with hesitation due to a bad fuel pump.

4. Smell Of Unburnt Fuel

Due to a bad fuel filter, the smell of unburnt fuel starts coming from the vehicle’s cabin or exhaust. A bad fuel pump doesn’t force fuel into the engine’s combustion chamber with enough pressure. Due to which the combustion process of the engine starts getting interrupted.

And due to the low pressure of the fuel, it is not ignited in sufficient quantity, due to which the smell of unburned fuel starts coming from the vehicle. Exhaust emissions from unburned fuel can also cause eye irritation.

5. Engine Stalling

Many times the engine suddenly starts shutting down while the vehicle is moving down the road. Because a bad fuel pump does not supply the engine with the required amount of fuel continuously.

And when the fuel supply stops in the engine while it is running, the engine starts shutting down suddenly. However, there can be many other reasons for an engine to stall. like an electrical or mechanical fault.

6. RPM Not Going Above A Certain Point

If you over accelerate your vehicle due to a bad fuel pump. Then the RPM of your vehicle does not go above a certain reading in the cluster meter. even if you press the accelerator pedal all the way down. This happens because higher fuel pressure is required to increase the engine’s RPM.

But a bad fuel pump does not send fuel above the specified fuel pressure to the injectors. Due to this, fuel is not supplied as per the requirement for acceleration.

Often, whenever a vehicle’s fuel pump goes bad, it causes the engine to misfire. Because for efficient operation of the internal combustion engine, the fuel pump sends fuel to the injector with high pressure, due to which the fuel ignites. But due to a bad fuel pump, the fuel supply gets disrupted and the engine starts misfiring.

What To Do if The Fuel Pump Fails?

If your vehicle’s fuel pump has failed, there are a few things you can do to fix it. But replacing a bad fuel pump is better than repairing it. Because most fuel pumps are not repairable. However, you can try some solutions to fix it in an emergency which are as follows:

• Check The Fuel Pump Fuse, Relay And Wiring: If a vehicle’s fuel pump is not working, the first thing you should do in your attempts to fix it is check the fuel pump relay and wiring. Because sometimes moisture or rust occurs in the relay, due to which the functioning of the relay gets disrupted. Along with this, also check the wiring and ensure that the fuel pump wiring is not broken anywhere. Because most fuel pump failures are caused by a bad relay or damaged wiring.
• Clean The Fuel Tank And Lines: If your vehicle’s fuel tank and lines are not clean, the fuel pump may be unable to function. Because there is a small filter installed on the fuel pump, which filters the fuel from the fuel tank and reaches the pump. But if there are rust particles or other debris in the fuel tank, it can prevent the fuel pump from drawing fuel. So if the fuel pump stops working, clean the fuel tank and lines.
• Check For Fuel Leaks: If there is a leak in your vehicle’s fuel lines, it will cause low fuel pressure, causing the fuel injector to not inject enough fuel and causing the engine to run rough or not start at all. So whenever you experience fuel pump related symptoms, be sure to check the fuel lines for leaks.
• Replace Fuel Pump: If the problem persists after trying all of these solutions, you may eventually need to replace the fuel pump. Since most fuel pumps are not repairable, your only option is replacement. However, you can also repair the fuel pump of some diesel engines.

If you are inexperienced with fuel pump related inspections and repairs, you should have your vehicle inspected and repaired by a professional technician. Because due to inexperience, there may be a problem of fuel leakage while changing the fuel pump.

FAQ For Fuel Pump

Below are some frequently asked questions related to bad fuel pump, which are answered with complete authenticity and will help you in completing your web search.