A fuel injector is an important component of the fuel injection system found in almost all modern automobiles.
A fuel injector takes over the task of supplying fuel to the car’s engine and usually if the car has a faulty fuel injector it can cause a lot of trouble.
In this guide, we’ll take a look at the basics of a fuel injector and how you can diagnose and take preventive measures to extend the life of the injector. First, let’s look at the signs:
The most common symptom of a bad fuel injector is a misfiring cylinder along with a check engine warning light on the dash. You may also notice a vibrating engine or a bad fuel smell at idle. If your engine stalls at idle, that could also be a sign.
Since the fuel injector is directly connected to the engine, any problem with the fuel injector will result in a vehicle malfunction.
Here is a more detailed list of the most common symptoms you may notice due to a bad or failing injector.
8 Bad Fuel Injector Symptoms
1. Check Engine Light
One of the most obvious symptoms is that the check engine light on your dash is flashing. If one of the fuel injectors is clogged or dirty and is not efficiently supplying fuel to the engine, an electrical signal is sent to warn the driver.
Please note that the check engine light may also be activated for other reasons. Therefore, it is recommended that you take your car to a garage and have it scanned for error codes.
If the check engine light is flashing, check the fault code memory with an OBD2 code reader. They don’t cost that much and you can read the fault code memory at home.
2. Engine Vibrates
If the engine does not receive enough fuel, it will begin to vibrate as soon as it has completed a full cycle. In turbocharged engines, a clogged or dirty fuel injector can have dangerous effects and cause detonation that can damage the engine.
When the engine is in turbocharged mode at higher rpm it requires a lot of fuel and if the fuel injector cannot do this, detonation can occur causing the engine to vibrate.
3. Faulty Engine
The engine will misfire if the fuel injector is dirty, clogged, or does not open properly. A misfiring engine will interfere with acceleration, reduce fuel efficiency and cause a loss of power.
This requires immediate attention as your engine could also start knocking and cause serious damage to your engine.
4. Bad Smell of Fuel
This symptom occurs when the fuel injector is leaking or the fuel injector is not closing properly. Excess fuel creates a bad smell, which is noticeable while driving.
It could be an exhaust pipe leak or an external leak in the engine compartment, both of which are fatal because they can cause your car to catch fire.
5. Higher Fuel Consumption
If you regularly monitor your fuel consumption, you will notice a decrease or increase in fuel efficiency due to a poor injector. A faulty injector delivers too much or too little fuel to the engine than required and reduces the vehicle’s fuel economy.
If you suspect that your fuel economy has changed, it may be due to a faulty fuel injector.
6. Engine rough idle/stuck
If you experience rough idle or the engine stalls at low RPM, it may be a faulty fuel injector. This is because the fuel injector can spray too much or too little fuel, creating a lean or rich mixture, which can cause the engine to misfire and stall.
7. Emission Test Failed
If the fuel injectors spray pattern changes and injects too little or too much fuel into the engine, your car most likely will not pass the emissions test. This is because too much or too little fuel will be enough to increase emissions, and the catalytic converter will not be able to do its job properly.
8. Fuel leak
If you see a fuel leak in the engine compartment, it may be due to a faulty fuel injector. Fuel injectors are often made of plastic and can crack, causing an external fuel injector leak. If you notice a fuel leak in the engine compartment, you must replace it immediately because otherwise it can cause an engine fire.
Understanding the fuel injection system
Your car’s engine uses an internal combustion process to run and uses two key elements: oxygen and fuel. Oxygen is drawn from the engine air, while fuel is drawn from the fuel tank. The air intake is responsible for supplying air to the engine. Since the oxygen supply varies, the task of the fuel injection system is to constantly vary the amount of gasoline to be supplied in accordance with the oxygen supply.
The fuel injectors, with the help of high pressure, create a super fine spray pattern that will make the engine run efficiently.
Cleaning of fuel injectors
In some cases, your fuel injector is actually clogged with dirt. This can be caused by a faulty fuel filter, which lets dirt into the fuel injector. In this case there is often a super small filter inside the fuel injector, which you can replace.
Another case is that the fuel injector needs some lubrication because it has been sitting idle for a while, especially if you have been driving on ethanol.
Remember, if you want to try an injector cleaning, the best way is to do it to all the injectors at the same time to avoid the different amounts of fuel sprayed after cleaning.
Some special workshops can clean the fuel injectors for you. However, I recommend replacing the fuel injector, because in most cases, the problem will reoccur within a year of cleaning the fuel injector.
Cleaning of Fuel Injectors
In some cases, your fuel injector is actually clogged with dirt. This can be caused by a faulty fuel filter, which lets dirt into the fuel injector. In this case there is often a super small filter inside the fuel injector, which you can replace.
Another case is that the fuel injector needs some lubrication because it has been sitting idle for a while, especially if you have been driving on ethanol.
Remember, if you want to try an injector cleaning, the best way is to do it to all the injectors at the same time to avoid the different amounts of fuel sprayed after cleaning.
Some special workshops can clean the fuel injectors for you. However, I recommend replacing the fuel injector, because in most cases, the problem will reoccur within a year of cleaning the fuel injector.
Fuel Injector Location
Fuel injectors are located on the intake side of the engine, below the fuel rail, which is often located in the intake manifold.
If you have a diesel car, your fuel injector is likely to be located in the cylinder head, but gas fuel injectors are installed in the intake manifold in almost all cases.
There are some rare cases where your car has direct injection and the injectors are installed in the cylinder head.
Fuel Injector Replacement Cost
The average fuel injector replacement cost is between $100 and $500, depending on the car model and labor costs. A fuel injector typically costs between $50 and $300. Labor in a shop typically costs between $50 and $200.
The cost of the fuel injector can differ greatly depending on whether you have a gasoline or diesel engine. Diesel injectors are often very expensive, which can result in part costs of $400 or more.
Replacing diesel injectors is also often more complex than replacing gas injectors, even if it can be difficult on some gas engines as well.
