How to Fix a Leaking Fuel Injector

An isolated fuel injector on a white background.
What You'll Need
O-ring repair kit
Two quick connect line repair kits
Fuel injector puller
New fuel injector

Whether you are aware of it or not, the vehicle you drive most likely contains something called a fuel injector. In the 1980s, vehicles ran with the help of carburetors. However, they were eventually all replaced by fuel injection systems.

The actual fuel injector itself can present a problem if it starts leaking. If you notice a problem, it is important to locate the source. Often times the fuel lines running to the injector will be the cause because they no longer seal properly, so this article will give you the tools the fix this malfunction yourself.

What Is Fuel Injection?

Fuel injection is the system in your vehicle that mixes fuel and air. Perhaps the most important thing to remember is that each and every fuel injection system is calibrated and set specifically to each type of fuel it will handle.

Step 1 - An Easy Fix

The first thing that needs to be done is to be sure the fuel system is depressurized. This is a simple task you can execute by allowing the engine to cool down and remove cap from fuel test port, wrapping it with cloth, and depressing valve stem until fuel quits flowing. Dispose of fuel soaked cloth properly. Another way to depressurize fuel system is to remove fuel pump relay or otherwise disconnect fuel pump electrically and start engine to use all remaining pressurized fuel in lines.

Step 2 - Remove the O-rings

From the firewall, you will see the return fuel line. You must first remove the quick disconnect fasteners. Then, when you remove the tube, you will find two orange O-rings inside. Remove them and replace them. Be sure to check the outlet line when you're finished and repair it if necessary.

Step 3 - Seal and Test It

With the new O-rings in place, use your quick connect line repair kit to replace and secure any of your lines. To test if the leak is fixed, simply insert the key into the ignition and turn it enough so that an electrical current is running through the engine; you don't want to turn over the engine. This is very important because you don’t want to accidentally ignite a fire if you have improperly mended your lines. With electricity flowing, check your fuel pumps for any leaking. If you find them clean then you have completed your task.

Step 4 - Remove the Fuel Injector Itself

If you find that this has not fixed your problem, it will become necessary to replace the injector itself. Locate your injectors, now you can use a fuel injector puller to remove the injector from the engine. Be very careful, though, because you don't want to break any of the expensive engine pieces located around it.

Next, insert the new fuel injector, making sure not to force anything into place. It will slide in once it settles properly. Then, you can reattach your fuel lines and everything should be good to go.