How to Check for Leaking Fuel Injector at Home and Fix Them: Symptoms, and Cost 2021

The fuel injection system is important for spraying the right amount of gas into your engine. When it goes bad or starts to leak, then your engine’s performance will change and you will develop a few different symptoms.

Symptoms like reduced gas mileage, white smoke, misfiring, and a bad scenario with erratic engine idling will happen if your car has an internal leak. Yet if you have an external fuel injector leak, the fire will start because it is not noticed on time.

To make sure your engine is running well, you need to check for fuel injectors that might be leaking. You can do this by reading on and finding out how to check for leaking fuel injector. These leaks can cause fires if they aren’t fixed.

How to Check for Leaking Fuel Injector:

A leaking fuel injector is an easy way to know that you have a problem. If you have a smell of gas or if your car stalls, it’s possible that there’s a leak. Here’s what to do if that happens:

The outcome of a leaky fuel injector will be that the fuel won’t get sprayed evenly and it might cause problems. The computer will send a message to the ECM and at this point, it is possible that there could be less fuel getting sprayed.

How to Check for Leaking Fuel Injector

The ECM will not know exactly which injector is spraying too much fuel, so it will reduce the amount of fuel that all the injectors are shooting into the engine. Since the ECMs has reduced only a little bit of fuel in comparison to what a non-leaking injector shoots, it’ll result in an engine misfire.

When this happens, computer stores a misfire code in the system. If you have codes P0301 for cylinder 1, p0302 for cylinder 2, p0303 for cylinder 3, and p04304 for cylinder 4 on your car’s control panel. The computer will turn up or down the level of gasoline that each injector is spraying. However, it is important to know how your injectors work. And how they will affect your engine.

That’s what we’ll do now. We’ll talk about the steps to take.

Step 1: Start your car. Watch the fuel injectors when it is running on idle. If there are any leaks, then you need to get a new O ring and replace the damaged ones.

Step 2: Turn off the car engine, and take off the battery negative terminal. Get rid of the air filter box that is in your way by taking off the screws that are holding it.

Step 3: If your car has a throttle cable, disconnect it. If there is a socket, unplug it. Unplugging the wires is important too.

Step 4: Unplug the socket for your injectors. Unscrew and pull off the fuel rail, then put on a remover. You need to leave some of the fuel lines attached so that you get an adequate amount of pressure from your pump.

Step 5: Get a syringe to measure the fuel pressure.

Step 6: Use your multimeter to test the voltage on your injector sockets. Most cars have two pins, and you want to see the numbers 3.70 and 3.89 volts in those pins. Anything above that is bad and needs to be fixed.

Step 7: Remove the fuse and take a close look at it. You will see two numbers on it, 87 and 30. These are the fuel lines (these numbers might be different for your car). Reattach the fuse to keep gas coming through.

Step 8: To measure your fuel injector, use a syringe that is marked in milliliters. Fill it with fuel up to 30-50 milliliters and let it start to flow into the container. The higher you fill the syringe, the better accuracy you will have for measuring your fuel injector.

Step 9: In this testing model, it is ideal to record the time that all of the injectors take to fill up a milliliter container. If you cannot use a milliliter container, you can use any other container instead. But you will need to watch closely. The spraying should be running smoothly and not have big drops coming out of it.

How To Fix Leaking Fuel Injector

To check for injectors that are leaking, you have to look at the part of the car that is leaking. If there is water or oil on it, then you should also find out what kind of leak it is and where it is coming from.

First, you need to inspect your injectors for leaks. Disconnect your battery so that there is no spark. Get your tools ready and take off the air box by taking out the screws holding it in place.

How to Check for Leaking Fuel Injector

Loosen the bolts on your throttle body. Unplug the socket or throttle cable depending on your car model. Take off the water and air hose, carefully unplug all of the sockets and wires, remove anything that’s blocking your way, and gently unplug the injector sockets to avoid breaking fitting pins.

Under the hood, look for a light. Take it and use it to look for any fuel on the side of your injectors. This is likely because there is something wrong with your o rings.

Loosen the bolts that hold the fuel rail. Gently pull it off and look at each o-ring individually. If an o-ring is damaged, you need to get new ones and replace the ones that are broken. You can replace all of them if you have original o-rings that will last a long time. A broken o-ring will make your car leak fuel. You want to replace it as soon as possible.

There are many steps to check for internal fuel injector leaks. Find any leaking injectors and replace them with new ones. The cost of the leaking fuel injector can vary, but it is usually affordable.

Depending on the car model and make, you can get your leaking fuel injector fixed with $600 to $1,250. If it is not leaking anymore, the cost will be around $400 to $900. But if it is still leaking, then the service fee will be around $200 to $250.

How to test a fuel injector in a BMW that is leaking.

How to Check for Leaking Fuel Injector – FAQ

Can you fix a leaking fuel injector?

Yes, you can fix a leaking fuel injector. The cost of fixing a leaking fuel injector varies depending on the type and how severe it is. It’s usually around $400 to $900 if there are no other problems found aside from the leaky fuel injectors.

How can I test my fuel injectors at home?

You can test your fuel injectors at home by using a syringe to measure how much pressure is coming out of it. When you use a multimeter, make sure that the voltage readings in both pins are around  –  37 volts and not above 40. Replace leaking injector sockets with new ones if they’re broken or leaky.

What is the solution for a leaking fuel injector?

The best way to fix it is by replacing your old, leaky fuel injectors with new ones. This will solve the problem and make sure you avoid any gas leaks in the long run. You can also replace all of them if they are original o-rings.

Can you drive with a leaking fuel injector?

Yes, you can drive with a leaking fuel injector. It is dangerous and will need constant servicing to fix it up but you might be able to get by for now because the leak won’t cause your vehicle to stop running or anything of that nature. To avoid any gas leaks in the long run, replace all old o-rings with new ones and make sure that the leaky injectors are replaced with new ones.

Final word

After you have read this how to fix a leaking fuel injector article, drive your car around for at least a mile and see if there is any gas leakage. If the leak persists even after that then look into getting it fixed as soon as possible because it will only get worse.

Fuel leaks can cause fire hazards and severe engine problems. If you find a leak, fix it quickly before it does more damage. You will use the steps that we have shown you to check for any leaks in your car and then fix them. Your questions are welcome, so don’t be shy!

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