As its name suggests, the job of a fuel injector is to inject fuel into the car – specifically, the combustion chamber. When they go bad, many symptoms may pop up in which case, you have to replace them. In this article, we talk about everything about fuel injectors, including what they do in your car, fuel injector replacement cost, potentially cheaper fixes, and more.
It would be hard to pinpoint an exact amount of fuel injector replacement as there are many factors to consider. To give a rough estimate, you will have to spend anywhere between $600 to $2,000 in fuel injector replacement costs. Sometimes, you will only need a flush and that is significantly cheaper, but more on that later.
Let’s start with the basics!
What Is A Fuel Injector?
Before we start on how much it costs to change fuel injectors, it would be helpful to know exactly what these components are and how they work. Usually, every cylinder comes with a fuel injector. Direct fuel injection is the common principle where fuel is directly injected into the ignition chamber. The fuel injectors can be considered the last piece of the fuel system and function in an accurate and controlled manner.
For effective and efficient combustion, the fuel is divided into many small particles through a process known as atomization, which is particularly necessary for diesel engines. When there isn’t enough atomization or the amount of fuel is less than needed, you will experience problems when driving.
Types Of Gas-Engine Fuel Injectors
There are 3 main types of gas-engine fuel injectors:
- Throttle body, or TBI: This is the oldest and simplest set-up. One injector sits inside the throttle body and delivers fuel to the engine. Diagnosing any problem in this is fairly easy and so is a replacement.
- Multiport fuel injector: There are separate injectors for each cylinder. Perhaps the most common set-up in today’s time, multiport fuel injectors have some advantage in efficiency over their older counterparts.
- Direct injection: One injector is used per cylinder, but rather than spraying into the intake system, the fuel is directly injected into the ignition chamber. This is a bit more efficient and is becoming more common. Cons include: intake valves need fuel spray to stay clean, and the injectors are affected by the conditions and pressures of the combustion chamber.
Similar to any other car part in today’s industry, there is an electrical part that might be faulty, ultimately causing a multitude of symptoms and signs.
Functions Of A Fuel Injector
The primary function of a fuel injector is to deliver fuel to the engine. The injector injects (sprays) fuel into the engine’s cylinder through a nozzle and that kickstarts the combustion process. The fuel has to be supplied in the right amount, at the right time, right spray pattern, pressure, and angle.
The Engine Control Unit or ECU is the “brain” or central computer of a vehicle and manages different individual components, like the fuel injector. It is the job of the ECU to ensure the injectors spray fuel at the correct time and in the correct amount through various sensors. The right air/fuel mixture needs to be created.
The fuel pump of a vehicle pushes gas into the fuel injectors through the fuel lines, from the tank. When there is a need for fuel detected by the ECU, it transmits this information to the fuel injector solenoid which opens up as a response. After that, the pressurized fuel is sprayed into the cylinder.
Common Signs Of A Bad Fuel Injector
If something were to go wrong with one or multiple of the fuel injectors in your car, the engine would not be able to perform the way it should. A bad fuel injector will either stop fuel from being spritz onto the engine altogether or it will cause unwanted intervals in the spray time. Either way, your car will not operate the way it would when it had a good fuel injector.
We have listed nine tell-tale signs of a faulty fuel injector that will tell you early on that you have a problem on your hands. Some of the signs of a dirty or clogged fuel injector can be similar so it’s best to first attempt using a good fuel injector cleaner on the fuel system.
Alternatively, you may have to pay a certified professional to clean the fuel injectors or even buy a cleaning kit for it to do it yourself. Whatever you choose, you must handle this issue as soon as possible so it does no serious damage to your car’s engine.
1. Engine Stalls Or Rough Idle
As your vehicle is denied enough fuel to function properly or even run, to begin with, the RPM will drop way below optimal levels when the engine is running. As a result, your car might display signs of rough engine idling where it will be shaking and stuttering even while staying still.
If the RPM is dangerously below the normal level, the car may stall and you would have to restart the vehicle. Unfortunately, this is a sign of higher fuel injector replacement costs to be incurred.
2. Engine Vibrates
If the fuel injector is damaged or faulty, the engine cylinder will not be able to fire at the correct time, or it may not fire at all. Due to this, your vehicle will shake and vibrate out of control when you are driving it as it tries to complete the cycle without adequate fuel. Without enough fuel driving the engine, the damage is done to the system, and fuel injector replacement cost increases.
3. Engine Misfires
If enough fuel cannot reach the engine due to a clogged or malfunctioning injector, the engine will start to misfire mid-drive. You will experience issues while accelerating your vehicle, especially when trying to go uphill or reach high speed. In addition, there may be a delay in acceleration once your foot has pressed the gas pedal.
Either way, you have to look into this issue as soon as you can. Failure to do so will drastically increase the chance of your vehicle suffering due to overheating problems. When a car is running on an incorrect blend of air and fuel, problems start showing up quickly.
4. Check Engine Light Illuminated
There are a plethora of reasons the check engine light of your car has come on. It might be a failed mass airflow sensor, faulty oxygen sensor, or many other reasons – both major and minor. Even if the reason behind the illuminated light is somewhat light in your book, try to get that checked by a professional quickly. Prevention is better than cure.
In this case, an obvious sign of an issue with the fuel injector in a car is a check engine light that’s coming on. There is a chance that the problem may be with the fuel injector if the light illuminates on your car’s dashboard, so don’t rule it out completely. As the efficiency of the engine is lowered, the light comes on.
Make sure that this is the problem you are dealing with before you spend on a new fuel injector or have your mechanic change it. You can use an OBD2 scanner paired with a diagnostic tool to confirm your doubts.
5. Fuel Leak
Apart from collision damage, a fuel injector can be cracked or broken due to general wear and tear. Needless to say, a condition like this allows gasoline to leak. As the fuel cannot reach the nozzle anymore, it drips out from the body.
If you inspect the fuel injector, you will see gasoline on the outside of the fuel rail nearby. Often, the leak originates from the fuel injector seal which goes bad over time.
6. Fuel Odor
This problem goes hand-in-hand with a fuel leak. The only difference is that a foul odor will come where there is unburned gasoline due to a faulty fuel injector or one that does not close anymore. You will get a strong smell of gasoline. Sometimes, the problem might be a bad sensor or fuel lines alerting the ECU to push more fuel than needed.
Either way, the cause of the odor has to be detected fast and repaired before it poses a big safety threat.
7. Engine Surge
A damaged fuel injector can not only spray too little fuel into the engine, but it can also spray an excessive amount. When this happens, the engine can surge and make the acceleration of your vehicle slower. Thus, the performance takes a hit. When you drive around, you will observe that the engine RPM fluctuates more than usual. Rather than staying at fixed RPM, it goes up and down too frequently.
8. Poor Fuel Economy
The fuel economy is a good indicator of vehicle performance. Any time something is wrong with your car, chances are, the fuel economy will show it. If you see that your car’s miles per gallon have decreased, in both city and highway driving, a bad fuel injector might be the villain.
An engine requires the right amount of fuel for the combustion process, and a bad one sends wrong signals to the fuel injector. If an injector sprays too much, the engine experiences strain and fuel economy decreases as the ECU is tricked into thinking it needs more fuel than usual to run.
9. Failed Emissions Test
Because a poor fuel injector can create an incomplete fuel burn, your car starts emitting more. In special cases, a leak in the injector can also make the fuel and air mixture a bit too rich, ultimately leading to a damaged and burnt-out catalytic converter. When you replace this component, it will significantly increase the maintenance costs of your vehicle as well.
Fuel Injector Replacement Cost: Cleaning Cost
Fuel injectors, much like many sensitive components of a vehicle, do not last forever. However, you can take steps to preserve their lifespan to the best of your capabilities. Many experts suggest that one clean their car’s fuel injectors once every 30,000 miles or so. This prevents dirt and deposit build-up on the component and allows the fuel to be sprayed into the cylinder.
For maintenance, one bottle has to be used around the time when you would do a regular oil change. However, if the fuel injectors are already displaying symptoms of being clogged, do it as regularly as you would fill the gas tank.
Fuel Injector Replacement Cost: Do Fuel Injector Cleaners Work?
Yes, they do! The majority of liquid cleaners contain chemicals that can break down different pieces of dirt and debris that disrupt normal injector function. Chemicals such as polybutene amine (PBA) that are included in cleaners can effectively clean:
- Fuel injectors
- Intake valves
In addition, it can help with:
- Lowering engine emissions
- Restoring engine power
Used regularly, a good fuel injector clean can help you remove unwanted pollutants in the system and prevent the build-up of new ones. They are more important for fuel-injected engines and engines operating on gasoline that has Ethanol.
Moreover, another chemical by the name of polyether amine (PEA), offers additional benefits, like reducing engine pinging and knocking, cleaning combustion chambers, solving cold-startup problems, and dissipating toxic sulfur remains from the gas gauge sensors.
Fuel Injector Replacement Cost: Professional Fuel Injector Cleaning
For more serious cases of clogged or dirty injectors, you have to invest a little in professional cleaning. This will cost you between $50 to $100 for one round. Some automakers allow you to send them your car’s dirty injectors and they will return it after giving it a thorough cleanse. Generally, they charge $15 to $20 for it.
They will surely be the best at this job but you want to consider the downtime from your vehicle.
Fuel Injector Replacement Cost: DIY Fuel Injector Cleaning Kit
As an alternative, full-time or part-time mechanics can buy a fuel injector cleaning kit that will pay for itself after some use. Getting the right kit is beneficial for car owners as it will come with various adapters to let you work on almost any fuel-injected engine.
When To Get Fuel Injector Replacement
Refrain from driving when the fuel injector of your car has failed. You will perhaps have to deal with a vehicle that stalls every other mile and it might not even operate. We mentioned the signs of fuel injector failure so keep an eye out for those. Moreover, if your vehicle is overheating, have that checked because it may be connected to a bad fuel injector.
Fuel injectors fail over time. Try to get them examined, if not changed, at least after every 100,000 miles. Make sure the mechanic has a look at the fuel injector(s) during routine car maintenance.
Fuel Injector Replacement Cost: How It’s Done
Injectors can be switched straight with replacement injectors or serviced after being removed from your car. To service injectors, specialized test equipment is required. You can choose to repair versus replace based on what exactly is wrong with the injector as well as your personal preference. Either way, the faulty injector has to be removed from the vehicle in the following steps:
- The process starts with a cold engine as the mechanic will relieve the pressure in the fuel rail by running the engine briefly with the fuel pump fuse out.
- A few parts are removed including the upper plenum on the intake manifold, connecting cables, wiring, or hoses that may restrict access.
- The return and supply lines are taken out. Then, the mechanic unlocks and removes the electrical connectors to the fuel injector before the injector is unbolted and extracted from the intake manifold.
- Any bad injector(s) is removed from the fail, making sure no debris can enter the exposed outlets. Generally, an O-ring seal secures the fuel injector tightly in place in a bore in the fuel rail.
- The replaced or services injector is re-installed into the fuel rail using a new O-ring. Engine oil is also used here to make sure no damage is done to the O-ring.
- The fuel rail is re-inserted and return and supply lines are re-connected. Similarly, the plenum goes back to its place alongside the wiring, hoses, and cables.
- Lastly, the mechanic runs the engine, carefully checking for leaks, and performs a road test.
Things To Keep In Mind When Replacing A Fuel Injector
- High-quality gasoline (Tier One) might decrease deposits on fuel injectors and therefore, prolong their life.
- If one injector has to be removed for the sake of repairing it, the best idea is to remove and service all injectors at the same time. In this case, the electrically failed fuel injector can be replaced while the others are cleaned. Servicing all of them at the same time makes sure the injector set is well balanced when it comes to flow rates. In turn, it promotes smooth engine operation.
- Stay away from fuel system cleaning chemicals or processes if your car manufacturer dictates against it in the owner’s manual.
- Off-the-car cleaning of fuel injectors is much more effective than on-the-car cleaning as injectors feature small internal filter baskets that have to be changed as a step of service.
Is It Safe To Drive With A Fuel Injector Problem?
Yes, you can drive with a fuel injector problem as long as the issue isn’t a malfunctioning component or a leak in the system. However, a bad injector can give rise to problems like excessive emissions, engine misfires, and more. A leaky injector can overheat and overload the catalytic converter. Furthermore, fuel efficiency reduces drastically when the fuel injector is not running properly.
Fuel Injector Replacement Cost
Luckily, most fuel injector problems can be solved with an O-ring replacement (given there is a leak there) or a professional cleaning. When there is a crack or leak in the fuel injector, however, replacement becomes necessary. Fuel injector replacement costs can be annoyingly high in some cases.
Although injectors work as separate components, they are designed to run in harmony with other injectors. This is why replacing one injector might call for a need to replace all the injectors. Have a word with your mechanic about that.
Depending on the model and make of your car, you can expect to pay about $800 to $1,500 for a total fuel injector replacement. The parts alone go for around $600 to $1,200 while the labor cost will come from $200 to $250.
Of course, there are exceptions. Non-OEM parts are cheaper and save you some coins in a few models/makes of vehicles. Finding a good part is the challenging bit, so, shop around for a while.
Sample Fuel Injector Replacement Costs
How To Save Money On Fuel Injector Replacement Cost
Mostly we recommend leaving the job of fuel injector replacement to the professionals. If you do want to save some money by DIY-ing this project, we advise against it. Exceptions apply if you have experience in handling car repairs and are aware of what you are doing.
In some instances, you can reduce some costs by comparing the prices of nearby mechanics. You might also be able to find some parts on your own for a cheaper price than what the mechanic is asking for them.
A faulty fuel injector will either stop supplying fuel or inject too little or too much of it. Whatever might be the case, the signs and symptoms will be too obvious to ignore. As these parts are inherently expensive, fuel injector replacement costs may not be light on your pocket. Along with the steep labor costs, the price of buying and having this part changed can become a hassle. However, it must be done for your safety. Do not disregard it!
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