How to Start a Car With a Bad Fuel Pump [3 Ways]

A bad fuel pump can make your car stall or unresponsive, making driving frustrating and stressful, especially on the highway.

As the name implies- the fuel pump – this component is usually located near the fuel tank and is responsible for pumping fuel from the gas to the engine. This means that, without a functioning fuel pump, your car would cut fuel at intervals (stall or misfire) or may not start at all.

This problem often arises when the fuel pump is clogged, damaged, or degraded, making it less efficient. It could also be a manufacturer defect, as I’ve seen a case where a car owner installed a new fuel pump, which malfunctioned the next minute.

A bad fuel pump can be temporarily fixed by applying manual pressure, maintaining the car engine’s heat, or using a fuel pressure gauge. However, you may need to change the fuel pump eventually for a seamless driving experience.

Notwithstanding, if you find yourself in a situation where you need to start your car with a bad fuel pump, there are a few things you can try.

Table of Contents

What is a Fuel Pump

As briefed earlier, The fuel pump is responsible for pumping fuel from the gas tank to the engine. It helps supply a good air-to-fuel mixture needed for combustion.

This can be either done mechanically using a low-pressure system or electrically using a strong electrical current depending on the fuel pump installed on your car, whichever way boosts the combustion process.

Therefore, once your fuel pump becomes bad, the fuel supply to the engine becomes excess or minimal, throwing off the air-to-fuel mixture ratio in the engine cylinders.

In this case, you may experience symptoms such as difficulty starting your car, engine stalling or misfiring, reduced fuel efficiency, and strange noise from the fuel tank.

Endeavor to resolve the problem at this stage because your car will not start once the fuel pump becomes wholly damaged.

How do I temporarily start my car with a bad fuel pump?

Before you embark on the below fix, know that this is viable only when your fuel pump is failing and not when the fuel pump is damaged.

If your fuel pump fails, the temporary fix is applying manual external pressure. This will help you take the car to an auto repair shop nearby.

Although there are other proven methods that you can employ to start a car with a bad fuel pump, we’ll be discussing just 3 of them.

Let’s take a look at some of these methods:

Exerting Manual External Pressure

This implies that you manually exert the pressure to start the car with an external source. This can be readily achieved by attaching an air pump to the gas tank and pressuring it.

Maintain the Car Engine’s Heat

Due to the uneven fuel-to-air mixture caused by the faulty fuel pump, your engine may overheat. A better way to eliminate this is to allow your engine to cool its temperature.

This may reset the fuel pump without necessarily applying external pressure to the gas tank.

Use a Fuel Pressure Gauge

An alternative method to determine if the fault is from your fuel pump is using a fuel pump pressure. It measures the pressure in the fuel system and can help determine if the fuel pump is working correctly.

If the fuel pressure reading is lower or higher than the recommended level (refer to your manual guide), it’s possible that your fuel pump is lousy and needs replacement.

While this may sound easy, using a fuel pressure gauge requires some knowledge and experience; if you don’t know how to go about it, you can refer to YouTube or leave the task to a mechanic.

How can you tell if your fuel pump is bad?

After starting a car with a bad fuel pump, it’s essential to understand the signs of a bad fuel pump. This will help you monitor and implement fixes faster.

Poor Gas Mileage

If the fuel pump goes bad, it’ll either introduce more or less fuel into the engine cylinders; when the fuel ratio is higher, it’ll cause reduced fuel mileage because of the wastage.

Hard Starting
Noises from the fuel tank
Engine stalling or misfiring
Loss of engine power
Unresponsive Engine

FAQs

How do you test a fuel pump directly?

You can use a fuel pressure gauge to test the fuel pump directly. Connect the fuel pressure gauge to the port and set the ignition to “ON.” Check the fuel pressure gauge for the correct reading specified in your buyer’s manual.

Can a bad fuel pump still work?

A failing fuel pump may still pump fuel, but the vehicle will experience difficulty starting due to a lack of pressure.

Can I drive with a bad fuel pump?

Driving with a bad fuel pump can be frustrating and stressful, and we won’t advise you to drive with it. Instead, call a mechanic to help you fix the problem instantly.

Can a fuel pump fail suddenly?

Yes, 70% of fuel pump failures are often sudden and unpredictable. Most drivers implement repairs on other components without suspecting the fuel pump to be the primary cause.