What Are The Symptoms Of A Failing Fuel Injector?

A broken or faulty injector, when ignored, can cause some serious damage to your car. It could lead to many problems, including overheating, poor performance, and eventual engine failure. 

To avoid that, here’s how you can identify a bad injector:

1. Reduced Engine Performance

A faulty injector will affect your car’s fuel system. As a result, you will find a noticeable drop in engine performance. 

This could manifest itself in several ways, including: 

• Rough idling
• Engine stalling
• Engine surge
• Periodic vibrations or ‘hiccups’
• Engine misfires
• Difficulty in acceleration 

While your car may not display all of these symptoms, it’s best to take note of its performance if you suspect a bad fuel injector. 

2. Check Engine Light Turns On

An illuminated check engine light can signal a faulty fuel injector, among other things. 

So, how do we know for sure? 

For one thing, you can monitor for other symptoms of a bad injector along with the CEL. However, you should consult your mechanic to be sure. They’ll use an OBD2 scanner to identify the issue. 

3. Fuel Leak And Odor

A cracked or old injector can cause a fuel leak. This could be due to damage from wear and tear or old age. Whatever the case, it can result in gasoline leaking from the main body instead of reaching the injector nozzle. 

If you physically inspect the fuel injector, you’ll notice traces of gasoline on its exterior body or near the fuel rail. It will also reflect a strong gasoline smell due to the leak.

A damaged old injector could also leak too much fuel into the cylinder, cause incomplete combustion, and foul the spark plugs. 

4. Reduced Fuel Efficiency

When the fuel injector fails to provide the engine with the sufficient amount of fuel it needs, the engine acts up in response. It will continue to put more pressure on the injector for more fuel injection than it needs. 

This affects the car’s fuel efficiency and consumption as the engine demands more fuel than the ECU thinks it needs. 

5. A Failed Emissions Test

A broken or leaking fuel injector can cause insufficient or incomplete fuel combustion. Naturally, this results in increased emissions by the car. 

In some cases, a fuel injector leak can also end up burning the catalytic converter. So a failed emissions test could potentially indicate a faulty fuel injector.

How Much Does A Fuel Injector Replacement Cost?

The cost of your fuel injector replacement will depend on the make and model of your vehicle. Generally, replacing fuel injectors can cost anywhere from $800 to $1500 depending on the repairs and labor costs. 

New fuel injector parts can cost anywhere between $600-$1200. To that, expect to pay about $200-$250 in labor charges. 

However, note that you don’t always need to replace the fuel injector. Sometimes, your mechanic may simply recommend a thorough cleaning of the fuel injection system.

How Urgent Is A Fuel Injector Replacement?

While you can drive with a faulty fuel injector for a limited amount of time, you really shouldn’t. 

Eventually, a faulty fuel injector will cause incomplete fuel burn and severely affect the engine performance. A bad fuel injector can also potentially damage the car’s spark plugs and foul them. It can even lead to engine failure and cost you thousands in repair.

4 Fuel Injector Replacement FAQs

Let’s go through some frequently asked questions related to a fuel injector replacement, and their answers:

1. What Is A Fuel Injector?

The fuel injector is an electronically controlled mechanical device that plays a key role in the combustion of the air-fuel mixture. As the name suggests, the fuel injector ‘injects’ the fuel into the engine to prepare the air-fuel mixture for combustion.

Here’s how it works: 

• The fuel injector is located in the intake manifold injection, just before the inlet valve. 
• When you press the gas pedal, your car’s throttle body coordinates with the fuel injectors.
• The throttle valve cover opens, and your fuel injector sprays fuel that mixes with the added air. 
• The air-fuel mixture then enters the engine’s combustion chamber, which is ignited for combustion. 

2. What Causes Fuel Injectors To Go Bad?

Most fuel injectors are made to last for over a billion cycles. This would mean that most car owners never have to worry about getting new fuel injectors. 

However, it’s possible to get a faulty fuel injector as driving conditions or vehicle type can influence its durability and lifespan. 

As with most parts, the primary cause behind a faulty injector can be wear and tear. As the fuel injector gets old, it can get dirty and clogged around its valve cover and injector nozzle. 

That said, there are a few factors that could cause premature fuel injector failure. 

They are: 

• Driving conditions and habits (heavy towing, stop-and-go driving, etc.)
• Poor fuel quality that can lead to debris contamination in the fuel system
• Lack of preventative maintenance and regular inspections

3. How To Replace A Fuel Injector?

Fuel injector replacement can be a complicated process to perform on your own. So unless you have a good grasp of how these parts work, it’s best to leave the fuel injection replacement to professional mechanics. 

That being said, here’s a general walkthrough for a fuel injector replacement: 

1. Before proceeding with fuel injector replacement, it’s important to relieve the fuel system pressure. This is done by disconnecting the fuel line (hose) and the fuel rail.
2. Make sure the engine is cold to touch and disconnect the battery. 
3. Next, remove any plugs that are connected to a wiring harness. Using pliers, disconnect the electrical connector on each injector.
4. To remove the fuel injector, you’ll have to lift the fuel rail off the intake manifold. It’s best to use fuel injector pullers to avoid damaging the injectors.
5. Examine the injector. To disconnect it from the fuel rail, pull at it in a gentle back and forth motion.
6. Before installing a new injector, dip the spraying tip of the replacement fuel injector in some engine oil. This will wet the seals, ensure the right fitting, and help prevent leaks.
7. Press the injector back into the injector rail and reattach both to the engine.
8. Bolt down the injector rail, reattach the fuel line and the wiring harness, and plug in the electrical connector.
9. Reconnect the battery.
10. Finally, adjust the key to the ‘on’ position and start your engine after 10-15 seconds. 
11. Once the engine drops to the idle RPM rate, turn it off. Inspect the new fuel injector for any leaks, and you’re done!

4. How To Clean A Fuel Injector?

An old injector doesn’t always need replacing. Sometimes, a thorough cleaning cycle can also restore it back to new.  

So, here’s how you can clean a fuel injector: 

1. Start by working with a cool engine in a well-ventilated area. 
2. Locate the injectors. First, disconnect the fuel pump from the engine, and then disconnect the injectors from the fuel pump. 
3. Next, disconnect the fuel pressure regulator (if your engine has one) and reconnect the fuel line.
4. Find the fuel port and attach the injector cleaner kit’s hose to it. Remove the fuel tank cap to prevent building up fuel pressure.
5. Start your engine and let the fuel injector cleaner work through it. This should take about 5-10 minutes.
6. Finally, disconnect the injector cleaner kit, close the fuel tank cap, and reattach the fuel pressure regulator and the fuel pump.
7. Finally, turn on your car and monitor engine performance. 

Remember, if a DIY fuel injector cleanup is not your thing, always get a mechanic’s help.