Updated at: 27-07-2023 - By: micdot

This article contains affiliate links. Using any of the links on this page will allow me to earn a small commission at no additional cost to you. Is it possible that a faulty fuel pump relay can cause a misfire? Understanding what a “Engine Misfire” is and how it occurs would help us answer this issue precisely, it appears. In the event of an engine misfire, the vehicle will shake for a brief period of time. It is not natural to feel a shaking or a quick hesitation in your car when the engine misfires. Errors with the ignition can be deadly, which is why they cause so much anxiety. Sensor failures, fuel delivery system malfunctions, mechanical problems, and a host of other factors can all result in engine misfirings.

For engine misfire to be fixed, you must first identify the problem and then correct it. Using an OBD2 scanner is the best way to find the problem.

Can a Bad Fuel Pump Relay Cause Misfire?

The fuel pump relay is part of the fuel systems, which work together to keep the engine running. The engine may misfire if the fuel supply to the engine is inadequate as a result of this relay failing or malfunctioning. Despite this, there are numerous additional possible causes of engine misfire. Identifying the root cause of your engine’s poor performance is so critical. You can proceed with the repair once the faulty component has been found.

It’s possible to fix the erroneous component by not performing a thorough troubleshooting to identify the specific culprit. A malfunctioning fuel pump relay can cause an engine to misfire, and this article outlines what to look out for.

What Are The Causes Of Engine Misfiring?

These are some of the most prevalent causes of engine misfire, and they’re all things that most drivers encounter.

1. Emissions Equipment Issue

Different emissions devices can be found in various current cars, and all of them can be used to reduce carbon emissions. The Positive Crankcase Ventilation (PCV) and Exhaust Gas Recirculation (EGR) systems are examples of this equipment (EGR). The misfiring of any of these systems can be caused by any bridge in any of them.

2. Faulty Ignition System

Spark plugs and the crankshaft position sensor are just two of the many parts of the ignition system. Engine misfiring is likely if any of these ignition system components becomes damaged or malfunctions while you’re driving.

3. Damaged Delivery System

A variety of mediums are used to transport fluids, liquids, and gases to the engine and other critical systems. The delivery systems are the means through which these compounds are transported to their final destinations. Air and fuel delivery systems are standard equipment in most automobiles. When any of these systems is incorrect, it suggests that the engine will be unable to propel a vehicle, and so, you may have misfiring.

4. Faulty Sensors or Modules

Components and systems in automobiles use sensors, cables, and modules to exchange information. If a sensor or module is defective, it might lead to frequent misfires. Misfiring can also be caused by malfunctioning mechanical components, as well as by bridged circuit connections.

Signs Of A Bad Fuel Pump Relay

The check engine light on your dashboard is one of the first symptoms that your fuel pump relay has failed. The check engine light might turn on for a variety of reasons, but it is vital to note that a malfunctioning fuel pump relay is one of those reasons. Fuel pump relay malfunctions can also be detected by looking for these symptoms:

Slowing down the car

When you’re driving, your automobile frequently cuts out.

As soon as you turn the key, there is no sound from the vehicle (if the relay is working, you should hear a smooth whining noise as you start the car). As soon as you turn the ignition key, you hear a “extremely loud” noise, which is a sign that the fuel pump isn’t working properly. A defective relay deprives the engine of fuel, making it impossible to start your vehicle. Misfire in the engine


If a bad fuel pump relay causes misfire, what does it tell us? Because it’s attached to the fuel pump, it can cause the engine to misfire, and a car that doesn’t have enough fuel can’t drive.