You may ask yourself, perhaps even searching for “What Happens When a Fuel Pump Goes Out While Driving?”, haven’t you? Well, search no more. This is a common query for many drivers who worry about potential vehicle failures during their journey.
So, what happens when the fuel pump goes out while driving? The vehicle will lose power, stutter, or even stall entirely due to the lack of fuel reaching the engine. The engine light might flash on, and you might notice a drop in fuel efficiency.
Why read this article? This guide will help you understand the signs of a failing fuel pump and provide practical advice on what steps to take when such a situation arises. Knowledge is power – being informed can help you manage such an event effectively, ensuring your safety on the road.
Table of Contents
What Does A Fuel Pump Do?
To better understand the potential issues you are running into, we’ll first take a deep dive into how a vehicle’s engine works, and the role the fuel pump plays in it. Here is the process your car goes through to move:
- Fuel is drawn from your gas tank to the engine through a line. In older cars, this happens through a mechanical fuel pump, moving the gasoline through suction. In newer models, there is a small electric motor that draws through the fuel line.
- Fuel moves through the fuel line towards the cylinder or carburetor.
- Air is injected to create a mixture with the fuel.
- The fuel and air combination combusts, firing up the piston in the engine. The piston starts moving faster and faster as it compresses the fuel mixture, and the spark plug ignites the mixture.
- The combustion powers the crankshaft, propelling the car forward. The fuel is now being burned off and expelled as exhaust.
Though this is a simplified version of the many steps that your car takes to move, this is a solid illustration of the importance of the fuel pump. If the fuel pump is malfunctioning, then the gasoline will sit in your gas tank. The process from steps two to five won’t even start.
What Happens When A Fuel Pump Goes Out While Driving?
Immediate Signs of Fuel Pump Failure
When a fuel pump goes out while driving, the most immediate sign is a sudden loss of power. This is because the fuel pump is responsible for delivering a steady supply of gasoline from the tank to the engine. When it fails, that flow of fuel is interrupted, starving the engine of the fuel it needs to run.
This can manifest as a sudden hesitation or stutter in the engine’s performance, particularly during acceleration.
Engine Misfires and Stalling
Another common symptom of a failing fuel pump is engine misfires or stalling, especially under stress or load. For example, when climbing hills or accelerating rapidly, the engine requires more fuel. If the pump can’t keep up due to failure, the car can jerk or shudder, or the engine might cut out altogether.
Starting Difficulties and Failure
If the fuel pump has gone out completely, the engine may fail to start. This is because the required amount of fuel isn’t reaching the engine to allow it to fire up. In other cases, the car might start but then stop shortly after, or it might require multiple attempts to start.
Poor Fuel Economy
Poor fuel economy can be a subtle sign of a fuel pump starting to go bad. If you notice that you’re making more frequent trips to the gas station and your driving habits haven’t changed, it could be because the fuel pump is having to work harder to get gasoline to the engine, thereby using more fuel.
Noise from the Fuel Tank
Abnormal noise from the fuel tank can indicate a problem with the fuel pump. If the pump is worn or damaged, you might hear a high-pitched whining or buzzing sound. This noise can be more noticeable when the vehicle is idling or starting up.
Overheating Engine
Finally, an overheating engine can be a symptom of a failing fuel pump. An insufficient fuel supply can lead to lean running conditions where there’s more air than fuel in the combustion chamber.
This can cause the engine to run hotter than usual, leading to overheating issues which can be detrimental to your vehicle’s health.
Knowing what happens when a fuel pump goes out while driving can help you identify and respond to these signs promptly. Remember, early detection can prevent more severe damage to your vehicle.
Are there any signs I can look out for?
Warning signs that your fuel pump is faulty can take many forms:
Sign 1: Sudden Loss of Power
A sudden loss of power, especially during high-speed driving or while climbing an uphill, could indicate a failing fuel pump. This is because the pump fails to maintain the required fuel pressure needed for optimal engine performance.
Sign 2: Engine Misfires
Engine misfires occur when the engine doesn’t receive adequate fuel supply. If your vehicle frequently misfires, it could be a sign that your fuel pump is starting to wear out. Misfires are typically accompanied by a jerking motion and can lead to increased emissions.
Sign 3: Difficulty in Starting
A clear sign of a failing fuel pump is when your vehicle struggles to start or doesn’t start at all. When the fuel pump is weak or damaged, it may not deliver enough fuel to the engine to facilitate the ignition process.
Sign 4: Poor Fuel Economy
If your car is consuming more fuel than usual, this could indicate that your fuel pump is not functioning properly. A faulty fuel pump may pump fuel inefficiently, leading to higher fuel consumption.
Sign 5: Noise from the Fuel Tank
Strange noises coming from the fuel tank can be a symptom of a bad fuel pump. A damaged pump might produce a high-pitched whining or buzzing noise, which is more noticeable when the vehicle is idling or starting.
Sign 6: Engine Overheating
A failing fuel pump can lead to lean operation conditions, causing the engine to overheat. If your vehicle frequently overheats, it’s a potential sign that your fuel pump might be on the brink of failing.
Sign 7: Vehicle Surging
Unexpected surges in speed while driving could indicate an issue with your fuel pump. This can occur if the fuel pump intermittently delivers more fuel than necessary, causing the vehicle to surge forward.
Sign 8: Vehicle Stalling at High Temperatures
If your vehicle stalls when the engine is hot, this could be a symptom of a failing fuel pump. As the fuel pump overheats, it can lose effectiveness, leading to a decrease in fuel pressure and eventually causing the vehicle to stall.
If you’ve noticed any of these symptoms, you should get an inspection and diagnosis from a professional. These warning signs can be anything from using bad or damaged fuel, to a clogged fuel filter, or worse. Usually, the longer you let your car work under these conditions, the worse the problem gets.
How To Diagnose A Failing Fuel Pump
Diagnose Step 1: Listen For The Pump
One of the simplest ways to diagnose a failing fuel pump is to listen. Turn on the ignition and listen for the fuel pump. If it’s functioning correctly, you should hear a faint whirring sound. No sound could indicate a problem with the pump.
Diagnose Step 2: Check Fuel Pressure
Checking the fuel pressure can provide a clear indication of the fuel pump’s condition. Using a fuel pressure gauge, measure the pressure in the fuel rail. A low reading could be a sign that the fuel pump is not working properly.
Diagnose Step 3: Test The Pump’s Electrical Circuit
Test the fuel pump’s electrical circuit using a multimeter. An abnormal reading could indicate that the electrical connection to the pump is faulty, affecting its performance.
Diagnose Step 4: Conduct a Fuel Volume Test
By measuring the volume of fuel that the pump delivers over a specified time, you can determine if it’s functioning properly. A lower-than-expected fuel volume could be a sign of a failing fuel pump.
Diagnose Step 5: Inspect for Contaminants in the Fuel
Contaminants in the fuel, such as dirt or rust, can damage the fuel pump. By checking the fuel filter and fuel tank for contaminants, you can identify if they are causing the fuel pump to fail. Signs of contamination in the fuel can point toward a failing fuel pump.
Diagnose Step 6: Check for Fuel Leaks
A leaking fuel line can cause a drop in fuel pressure, making the fuel pump appear as if it’s failing. Inspect the fuel lines for leaks. If leaks are found, they need to be fixed, and then the fuel pump’s operation should be re-evaluated.
Diagnose Step 7: Professional Diagnosis
If you’re still unsure about the condition of your fuel pump, it’s advisable to seek professional help. Auto technicians have specialized tools and experience to accurately diagnose fuel pump issues. Having a professional diagnosis can help ensure you’re not replacing a fuel pump that isn’t actually faulty.
12 Signs Of A Bad Or Failing Fuel Pump >> Check out the video below:
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Final Thoughts
In an ideal world, your fuel pump will last the lifespan of your car. Unfortunately, wear and tear can happen despite your best efforts. If you’re having issues with your fuel pump, bring your vehicle to professionals for a proper diagnosis.