Fuel injectors are responsible for delivering measured quantities of fuel into the cylinders of the engine, ensuring the correct air-fuel mixture for combustion, performance, and efficiency.
In that case, ignoring the symptoms of a faulty fuel injector can be damaging to the car as a whole, leading to higher eventual repair and running expenses. In this article, we will learn about how to detect the signs of a faulty fuel injector in a car, why ignoring these symptoms is not advisable, how and when to replace it, and what the associated costs may be.
What is a Fuel Injector in a Car? Components and Functions Explained
A fuel injector is a device that sprays precise amounts of fuel into the engine, ensuring the right air-fuel mixture for efficient combustion. Positioned above the intake manifold, it delivers fuel in the form of a fine mist, making it easier to burn.
In the current era, the functioning of fuel injectors is controlled by the vehicle’s electronic control unit (ECU). Depending on the data obtained from sensors regarding speed and load, the ECU triggers the fuel injectors to spray the required amount of fuel into the engine with split-second precision.
Key Components of a Modern Fuel Injector:
- O-rings and seals: Secures the fuel injector in its place, and prevent fuel leakage.
- Nozzle: A fine opening at the tip of the injector that atomizes fuel into the cylinder.
- Filter: Collects the impurities present in the fuel before it reaches the nozzle.
- Electromagnetic coil: Receives an electronic signal from the ECU and decides when to open the valve.
- Valve: Regulates the exact flow of fuel through the nozzle
Signs of a Faulty Fuel Injector in a Car
A failing fuel injector disrupts the balance of the air-fuel mixture, leading to poor combustion. If ignored, it can increase fuel costs and even cause long-term engine damage. Here are the most common symptoms of a bad or worn-out fuel injector:
1. Engine Misfires
The irregular timing and unusual functioning of a worn-out fuel injector can lead to engine misfires, as a result of which you might feel jerks and vibrations while idling or driving.
2. Weak Acceleration
A clogged or faulty injector can create a lean air-fuel mixture, leaving the engine underpowered. You may notice sluggish acceleration and inconsistent power delivery
3. Drop in Fuel Efficiency
Since the combustion process depends on the correct air-fuel ratio, a malfunctioning injector can cause the engine to burn fuel inefficiently. This leads to noticeable drops in mileage.
4. Fuel Smell Around the Engine
If you sense a strong smell of gas near the engine bay, it can indicate a leaking injector. This can happen if the injector body is cracked or if worn O-rings and seals allow fuel to escape.
5. Difficulties in Starting the Engine
The excess or reduced fuel sprayed by a faulty fuel injector can also make the job of spark plugs difficult, resulting in the engine taking longer than usual to start, or, in the worst cases, not starting at all.
6. Check Engine Light
Repetitive engine misfires, abrupt changes in air-fuel ratio, and irregular fuel spray timing within the engine can trigger the ECU to illuminate the check engine light. This warning allows you to address the issue before it causes further damage.
7. Excess Smoke from Exhaust
Due to an erratic air-fuel mixture sprayed by a faulty fuel injector, there is a chance that unburnt excess fuel will exit the exhaust in the form of black smoke. This is caused by poor atomization and incomplete combustion.
Causes Behind the Fuel Injector Going Bad
Besides the inevitable wear and tear, which is a significant reason for the deterioration of a fuel injector over time, several other external and indirect factors can affect its functioning and lifespan.
Here are some of the primary causes behind the ill-functioning of a fuel injector:
Faulty O-Rings and Seals
The rubber O-rings and seals that hold the injector in place can shrink, harden, or crack over time. Once damaged, they may cause fuel leakage around the injector.
Contaminated Fuel
The fuel injectors come equipped with small filters to trap dirt and debris from the incoming fuel. However, suppose this filter becomes clogged, along with the nozzle. In that case, contaminants can scratch or damage the injector, disrupting the air-fuel ratio and reducing the fuel injector’s efficiency.
Electrical Faults
External electrical faults, including incorrect or ill-timed signals from the ECU, a worn-out electromagnetic coil, faulty wiring, or damaged connectors and wires, also impact the functioning of a fuel injector. Since fuel injectors rely heavily on electrical signals from the ECU, such concerns can compromise their functional efficiency and potentially damage them.
Engine Overheating
In instances of engine overheating, the fuel injectors often bear the brunt, given their sensitive positioning above the intake manifold. Continuous exposure to heat accelerates wear on internal parts and can cause premature failure.
Driving with a Defective Fuel Injector: Is it Safe?
A fuel injector is one of the key components of a vehicle’s engine that ensures smooth operation with proper combustion. Each cylinder has its own injector, so technically, you may still drive if one fails. However, prompt action against the symptoms of a faulty fuel injector is highly recommended to avoid serious engine issues from developing over time.
Risks of Driving with a Faulty Fuel Injector:
- A malfunctioning injector can cause the engine to run too lean or too rich, resulting in misfires, reduced power, and poor fuel efficiency.
- Prolonged irregular combustion can stress engine components and even overheat the catalytic converter.
- A faulty fuel injector can also lead to hazardous situations, such as engine stalling while driving. Therefore, rather than continuing to drive with a faulty fuel injector, it is advisable to avoid such a situation and replace it with a new one in the interest of your vehicle’s engine performance, fuel efficiency, and durability.
Steps to Fix a Bad Fuel Injector in a Car
While fixing a faulty fuel injector, it is worth noting that its symptoms of ill-functioning can often be cured by cleaning, rather than replacement. However, for either, you will require professional assistance..
Step 1: Diagnosis
A service center will first check your car using diagnostic tools to figure out whether the injector can be cleaned or needs replacing. This helps avoid unnecessary replacements
Step 2: Relieving Fuel System Pressure
For safety, the mechanic will relieve pressure from the fuel system before touching the injector. This prevents fuel from spraying when parts are removed.
Step 3: Removing the Injector
The fuel injector will be carefully taken out of your engine. This usually involves disconnecting some covers, hoses, and wiring.
Step 4: Cleaning or Replacing the Injector
If the injector is in good condition, it can be cleaned to remove deposits and restore proper fuel flow. If it’s too worn or damaged, it will be replaced with a new injector. During installation, the seals (O-rings) are lubricated to ensure a smooth fit.
Step 5: Reassembly and Testing
Once the injector is cleaned or replaced, everything is put back together, and the engine is started to ensure it’s running smoothly.
How Much does a Fuel Injector for a Car Cost?
The cost of replacing a fuel injector can vary depending on your car’s make and model, the type of injector, and labor charges at the service center.
- For cars, the cost of replacing a faulty fuel injector ranges from $750 to $1,000, including $500-$600 for the parts and $150-$200 for the labor required to install them.
- Since fuel injectors for diesel engines operate at higher pressure levels and are more durable, they are costlier than the fuel injectors of gasoline engines.
- In some cases, replacing all the fuel injectors of a vehicle at once is a more feasible option than replacing just one injector, as it saves on labor costs.
Prevention of a Fuel Injector from Going Bad: Here’s How You Can Do It
The key to keeping your vehicle’s fuel injectors running optimally and for a long time is correct and timely maintenance of your car. In that sense, following some preventive measures, such as using high-quality fuel, replacing the fuel filter when necessary, cleaning the fuel injectors when required, and using suitable fuel additives, will help maintain the health of the fuel injectors and the engine overall.
FAQs
How can you tell if your fuel injector is bad?
Symptoms such as engine misfires, a drop in acceleration and fuel efficiency, a fuel smell around the engine, difficulty starting the engine, the check engine light turning on, and the vehicle emitting excess smoke are signs of a faulty fuel injector.
How do you unclog a fuel injector?
There are dedicated fuel injector cleaners available on the market, which are oils that can remove the dirt accumulated on the nozzle and filter of a fuel injector.
What is the lifespan of fuel injectors?
Fuel injectors for cars typically last between 50,000 and 100,000 miles, with their exact lifespan depending on the vehicle make and model, driving behavior, and periodic maintenance records.
Can I clean injectors without removing them?
To effectively clean the fuel injectors, it is required to uninstall them by disconnecting the rubber hose from their rail side. For internal cleaning of fuel injectors, flush them with fuel injector cleaners to remove the dirt deposited within them.
How much does it cost to replace fuel injectors?
For cars, the cost of replacing a faulty fuel injector ranges from $750 to $1,000, including $500-$600 for the parts and $150-$200 for the labor required to install them.