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Winter is a favorite for many people, but not for vehicles. It brings many issues when outside is cold. You may experience traction issues with tires and a dead battery.  But Fuel issues are also common in winter. When you park your vehicle in cold, fuel may freeze, and the fuel pump will stop working. Don’t worry; you can fix the issue if you know how to troubleshoot the fuel pump not working when cold.

First, identify the cause of the fuel pump problem. Check for frozen fuel, dead fuel pump, low fuel volume, and pressure. Once the problem is identified, fix it accordingly.

Fixing the fuel pump issues because of cold is not a complex job. Let’s have tea and read how I solve the fuel pump issue.

What can cause a fuel pump not to work?

fuel pump not working when cold

Your vehicle’s fuel pump can be faulty for several reasons. Here I have listed some of the major reasons which cause a fuel pump not to work.

Freeze Fuel Lines:

In cold weather, water collects in the fuel lines. If the temperature goes too down, this water freezes and stops the fuel supply through the fuel pump.


If you have low-quality fuel, then you may experience a gelling problem. When the temperature drops, paraffin evaporates from the fuel and becomes gel-like. Such fuel hardly moves through the fuel pump, which makes the pump not work.

The two above are the most common causes in winter, but it is not must you always have such problems. Here are a few other causes that may make your fuel pump not work; you may also check for these if the fuel pump does not work in the cold.


Fuel may contain contaminations because of debris, corrosion, and moisture. It makes fuel dirty, and fuel tanks fill with such contamination those problems in fuel flow.

Clogged Filters:

Clogged filters can cause the fuel pump not to work. When contaminations accumulate in the filter, it causes clogging. The fuel pump cannot properly maintain the fuel flow.

Electrical Problems:

Your fuel pump may also not work because of electrical problems. Some common electrical problems are loose connectors, rusted or corroded connectors, and melted wires or connectors.

How Do You Know if Your Fuel Pump is Not Working?

It is not just every time your vehicle has a problem with the fuel pump when not starting in the cold. Before setting out for a fuel pump problem solution, you must confirm your problem with the fuel pump. 

Here I have listed a few major signs that tell you the fuel pump is not working and needs to be checked.

  • The vehicle won’t start
  • Mileage drops than normal
  • Vehicle dies or sputters while driving
  • Overheating of engine
  • Speed could not maintain
  • Hear whining in the backseat of the vehicle
  • Engine performance decreases
  • Power loss during driving
  • Noise from the Fuel tank

How do you troubleshoot a fuel pump?

why fuel pump not working

Troubleshooting a fuel pump is simple if you know why it is not working. You have to check for all possible problems to get rid of the problem. Here I have listed some of the major problems which may make your fuel pump not work.

  • Freeze fuel in fuel lines
  • Faulty or damaged fuel pump
  • Low Fuel pressure
  • Low Fuel volume

Things you need:

Replacement Fuel pump Assembly [ If the fuel pump is dead or damaged]

  • Wrench
  • Screwdriver
  • Gloves
  • Jack or Jack Stand
  • Epoxy putty
  • Fuel pressure tester/ meter

You may find multiple options to choose from different fuel pump brands. But I recommend you Denso 950-0100 Fuel Pump. It is an excellent choice and a durable item. It is simple to install and performs well with most vehicles.

Epoxy putty is a simple item to fix the leakage in the fuel pump. You can buy from local stores. But I recommend you J-B Weld SteelStik for repairing the fuel pump leakage. It will give you a quick and durable seal over the leaked surface. You will find it resistant to fuel and temperature.

My recommendation for the pressure gauge meter is AUTO METER 2663. It is simple to connect and measure the fuel pressure and volume.

Problem 1: Freeze Fuel in Fuel Lines

In the winter, a common problem many vehicle owners face is fuel freezing in fuel lines. If the fuel freezes, it will close the fuel line, and fuel flow will be stopped or become low. But for the proper functioning of your vehicle, it needs to be solved. 

Solution 1:

It is pretty simple, but it takes time to solve the problem when you experience freezing of fuel in fuel lines. Here I have provided three easy ways to fix such an issue.

  • The first method is to bring your vehicle to a hot place, such as a garage where the temperature is higher. After a few minutes or hours, fuel will melt, and the flow will be smooth.
  • But it is hard to take a big car or truck to the garage or other place in such a freezing environment. So if it is not possible, then try the next method.
  • You will need heat to melt the fuel. You can use the stove, or a portable heater can help eliminate the problem. 
  • The final method I will share is filling the fuel in the fuel tank. When you add new fuel, it will melt the already available fuel. 

Problem 2: Faulty of Fuel Pump

If you have a damaged fuel pump, it would not be possible to maintain smooth fuel flow to the engine. Ultimately you will be unable to start the vehicle until you solve the issue.

Solution 2:

  • Check for the fuel pump; the fuel pump is located near the fuel tank. It is connected between the engine and the fuel tank.
  • Thoroughly check the fuel pump; there should not be severe damage or leakage.
  • If there is minor leakage, you can fix it using epoxy putty or tape.
  • But if the fuel pump is dead or damaged, then replacement is a must

Problem 3: Low Fuel Pressure

It is essential to have good fuel pressure for a smooth fuel supply from the tank to the engine. If the pressure is low, supply will also remain low. So you may face a problem starting the engine.

Solution 3:

  • Take the fuel pressure tester and insert it into the fuel tank
  • Check the pressure of fuel on the meter
  • It should be between 4 to 5 PSI; if the pressure is low, you may have bad fuel or frozen fuel, or the pump is leaked
  • Replace the fuel if fuel is bad; for frozen fuel and a leaking pump, use the above methods to fix

Problem 4: Low Fuel Volume

Low fuel volume can be the cause of the fuel pump not working. Low fuel volume causes a low fuel supply to the engine; ultimately, engine performance will also affect it.

Solution 4:

  • Open the Fuel tank cap and check the fuel level
  • Insert the fuel Gauge meter inside the tank
  • It is okay if the fuel is above or up to the recommended level. But if the fuel level is low, you should refill the fuel up to recommended fuel level

How to check if the fuel pump is working?

You can check it by noticing the humming sound from the fuel pump. Ask someone to turn the key and try to listen to the fuel pump sound. Your fuel pump is working properly if you have listened to the sound.

Frequently Asked Questions (FAQs):

Is a fuel pump not working when hot?

Yes, it is also possible when the fuel pump overheats, it also affects the fuel supply to the engine. You may experience running off the vehicle on the road if the fuel pump overheats.

Why is the fuel pump not working on the toy hauler?

It may happen because of electric issues or a clogged fuel pump. If the fuel pump is clogged and there is dust, debris, and contaminations fuel supply will decrease. So when you apply more power vehicle will stop instead of running.

Do fuel pumps just quit working?

When you notice the warning signs, it is better to replace the fuel pump. If you fail to replace it timely, you may experience fuel pumps just quitting working.

What will stop a fuel pump from working?

Frozen fuel, clogged fuel lines, contamination, and bad fuel can cause the fuel pump to not work.

Can you reset the fuel pump?

Yes, you can reset the pump. Switch off the vehicle, go to the panel and push the reset button for a few seconds fuel pump will reset.

Final Verdict

Smooth driving is impossible if you have a problem with your vehicle’s fuel pump. It is essential to troubleshoot the problem when you notice the warning signs. Fixing the fuel pump issues is not complex if you have the right tools and follow the proper instructions. It will save you money and time.

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