If your car won’t start, there could be many different reasons why. One of these could be a faulty or broken fuel pump. In this article, we’ll focus on this problem and how you can start your car even if it has a bad fuel pump. At the very least, starting your car will enable you to drive it for a short time until you can get it fixed or will enable you to troubleshoot the fault and figure out how to fix it.
Before moving on we’ll assume there are no other problems with the car, such as electrical problems which might need you to jump-start the car by connecting it to an external battery.
If your car has a faulty fuel pump you may have noticed some of the signs which can include poor acceleration, jerkiness when driving, and problems with starting the car. Do these symptoms sound familiar? Then read on to learn more about what the fuel pump does and what you can do to start your car when the fuel pump is faulty so that you can get it fixed.
Starting a car with a bad fuel pump is not as difficult as it might seem. This is a temporary solution and your fuel pump will need to be serviced, repaired, or replaced as soon as possible. The best ways to start your car include letting the engine cool, forcing air pressure into the engine, and attaching a pressure gauge.
Before we take a look at exactly how you can start your car with some of the methods above, let’s first look at what the fuel pump does and what happens when it stops working.
Table of Contents
- What is a Fuel Pump and Why is it Important?
- How to Understand if Your Car has a Faulty Fuel Pump?
- What You Should Do if Your Car Has a Problem with the Fuel Pump
- Ways to Start Your Car With a Bad Fuel Pump
What is a Fuel Pump and Why is it Important?
A fuel pump is a device that pumps liquid fuel from the tank to the engine. It is usually electrically operated and mounted inside the gas tank. Without a functioning fuel pump, your vehicle will likely stop or run unevenly as the engine cannot get the correct amount of fuel it needs to run properly.
Even worse, in some cases the fuel pump may stop working completely starving your energy of fuel and it will stall and refuse to start again.
Fuel pumps are powered by electricity and they draw fuel from underground storage tanks. Fuel is sucked up through pipes and sprayed into the car’s engine. Exactly how this functions and which type of fuel pump you have will depend on the model of car you have so be sure to check this in your car’s handbook.
Fuel pumps actually do more than just pump fuel; they draw liquid out of the tank, compress it, and force it into the engine through rubber hoses. As the fuel is drawn out of the tank, the air is sucked in to replace it, which creates plenty of pressure for forcing liquid fuel up through hoses and into your car’s engine.
The reason why a faulty fuel pump can make starting the car more difficult is simply that for the engine to start, it needs a shot of fuel to ignite a spark in the combustion chambers in each cylinder of the engine so that the engine can turn. It is the supply of fuel from the pump that also keeps this process going. No fuel, no power.
How to Understand if Your Car has a Faulty Fuel Pump?
Old cars usually had a mechanical fuel pump located on the engine, whereas newer cars will have a fuel pump either near or inside the fuel tank itself. Cars that have fuel injection systems normally have two fuel pumps, one for higher and one for lower pressure. The high-pressure pump controls the fuel injected into the engine and the low-pressure fuel pump moves the fuel from the tank to the engine.
A fuel pump is an integral part of any car’s fuel system. It pumps the gasoline from the gas tank to the engine, where it is mixed with air and ignited by a spark plug. When it pumps the fuel, air pressure is created in the system.
One way of diagnosing if your fuel pump is working correctly is by measuring the air pressure developed in the car’s fuel system. If the fuel pump begins to malfunction, the air pressure will drop and if you have zero pressure in the engine, it is a good indication that your fuel pump is completely dead.
A bad fuel pump can cause some or all of the following:
- The car has a hard time starting up and often has trouble staying running.
- The car’s engine may stall or run very poorly under load for an extended period of time.
- You may experience jerkiness when driving your car.
- A check engine light or “service engine soon” light appears on the dashboard when the vehicle is started.
- The engine fuel pressure will be low in an engine that has a bad fuel pump. You can check this with a fuel pressure gauge. Check in your car’s handbook the correct reading for your car and compare this with the reading you get.
- Excessive fuel consumption can result if the fuel pump works but supplies too much fuel to the engine. This is known as running rich.
- In addition to the above another symptom of a fuel pump supplying too much fuel is extra pollution coming from the engine exhaust.
What You Should Do if Your Car Has a Problem with the Fuel Pump
The most important thing to do if you discover you have a faulty fuel pump is to get this fixed as soon as possible. Whether you do it yourself or take it to a mechanic, leaving it for any length of time can damage your engine and cost you quite a bit of money. So put this off!
In some cases, a car with a bad fuel pump may start but then stall during operation or refuse to turn on altogether. In these instances, it’s best to replace the fuel pump as well as check for other issues that may be causing engine problems.
If the problem strikes suddenly and your car won’t start, there are one or two things you can do to start the car to allow yourself to drive it to where it can be fixed, or to get it home.
Ways to Start Your Car With a Bad Fuel Pump
It is a common misconception that a car cannot be started if the fuel pump is bad. A car can be started but it may not have enough power to keep going smoothly, so this is very temporary. A car’s fuel pump, however, is only one of many components for starting a car. In order for a vehicle to start, there needs to be an ignition system, battery power, and air intake.
Here are some ways to get your car started with a bad fuel pump:
- The most simple and easiest way to start the car is to wait and allow the engine to cool down. Most cars with a faulty fuel pump tend to cut out or experience problems when the engine gets hotter and letting the engine cool down can help get the pump back to a point where it will work more efficiently and allow the car to start and run temporarily.
- You can try to force pressure into the engine to help the fuel pump to operate and start the car. This will require a few tools, such as an external pump you use to blow air into a mattress. First, unscrew the fuel filter and place the pump into the fuel line. Pump air three or four times into the system and quickly reconnect the filter and try to start the car. Be aware that pumping air into the fuel line is tricky and this will cause liquid to shoot out so you will need to screw in the filter and replace everything quickly. Here is a video showing how this is done.
- Another relatively simple way to start a car that has this problem is a kind of spooky voodoo! All you do is attach a pressure gauge to the engine’s fuel system and often you’ll be able to start it. This will also confirm if the fuel pump is the issue because if pressure is low, that’s most likely the issue. There’s more about measuring fuel pressure and what it can tell you on this page.
- Here is one final thing you can try, and there are many accounts of it working on a fuel pump that has stopped working. You can hit the bottom of the fuel tank where the fuel pump is and the car may start! The reason why is that the motor inside the pump can jam and stop working and hitting it can suddenly free it. If you’re lucky it may come back to life. Make sure you fix it as soon as possible because you don’t want to rely on this method to get on the road again!
In most situations, one of the above methods will most likely start your car, however, if your fuel pump is completely dead you probably won’t be able to start the car. Help will then be needed to get you moving again. Time to call someone in!
Also, some cars will be easier to start than others. For example, a Chevrolet may start easily because its engine requires heavy-duty batteries and most of its power comes from the electric motor which has been installed in the transmission. The ignition coil provides high voltage from the battery to spark plugs which emit a current that ignites compressed fuel gases in the cylinders.
With any luck, this information has enabled you to get your car started, or at least you will now know what to do if you get stuck with a faulty fuel pump and a car that doesn’t start.
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