Fuel Injector Replacement: Corolla Maintenance Must-Know

Fuel injectors regulate the amount of pressurised fuel used for each engine cycle and, on average, they tend to fail after 80,000 miles. When replacing fuel injectors, it is recommended to use high-quality, OEM parts to ensure even power across the engine. The cost of replacing a fuel injector varies depending on the year of the Toyota Corolla and the location of the replacement, but it typically ranges from $546 to $613, with parts priced between $420 and $455, and labour costs between $126 and $159.

Fuel injector replacement cost

The cost of replacing fuel injectors can vary depending on several factors, such as the make and model of your vehicle, the severity of the issue, and your location. On average, the cost of replacing a fuel injector ranges from $300 to $900, with some estimates giving a range of $500 to $2,500. The cost of the parts and labor for the replacement typically ranges from $150 to $400, but in some cases, the parts alone can cost several hundred dollars each.

For example, the average cost of replacing the fuel injectors in a Toyota Corolla is between $546 and $613, with labor costs estimated between $126 and $159, and parts priced between $420 and $455. In contrast, the cost of replacing all four fuel injectors in a 2019 Toyota Yaris was quoted at $2150+tax, with the fuel injectors alone costing $1133.96.

It is important to note that attempting to replace fuel injectors yourself can be dangerous and may cause further damage to your vehicle. It is recommended to seek a professional mechanic for this type of repair.

Symptoms of a bad fuel injector

Fuel injectors are responsible for delivering fuel to the internal combustion engine. Over time, they can become clogged by dirt and debris, leading to poor vehicle performance. Here are some symptoms of a bad fuel injector:

Engine misfires

A bad fuel injector may cause the engine to misfire as it cannot maintain the correct balance of fuel and air entering the engine. This will cause the engine to sputter and send vibrations through the car.

Rough idling

Rough idling is characterized by varying RPMs, even when your foot is off the gas pedal. A bad fuel injector will cause the engine to operate unevenly, resulting in a rough idle. This may be accompanied by engine stalling, where the RPMs and engine noise suddenly stop, similar to running out of gas on a hill.

Poor fuel economy

A bad fuel injector will impact the air-fuel ratio, leading to decreased fuel mileage. Well-performing fuel injectors help your vehicle achieve optimal fuel efficiency as advertised by the manufacturer.

Difficulty starting

A clogged or damaged fuel injector may not deliver enough fuel to the cylinders, disrupting the air-fuel ratio and preventing the engine from generating the necessary combustion to start. In severe cases, the engine may not start at all.

Poor acceleration

A bad fuel injector may not provide the proper amount of fuel for combustion, resulting in sluggish acceleration and a lack of responsiveness when pressing the accelerator.

Unusual exhaust smell

A damaged fuel injector can cause an unusual smell from the exhaust as excess or unburned fuel is released through the exhaust system.

Check engine light

The check engine light is a clear indicator of a problem with the vehicle. If the fuel injector is malfunctioning, the check engine light will illuminate, indicating that there is an issue with the fuel delivery system.

Fuel leak

A crack in the rubber seals or the fuel injector itself can cause a fuel leak. If you notice any signs of a fuel leak, be sure to inspect the fuel injector for damage.

Fuel injector maintenance

Fuel injectors are responsible for pumping fuel through an electronically controlled opening that sprays the fuel into the cylinder. This allows the fuel to burn more efficiently and evenly. Over time, carbon buildup and other gunk can clog the injectors, reducing their ability to adequately provide fuel to the engine.

To maintain your fuel injectors, it is recommended to get a fuel injector cleaning service after every 60,000 to 90,000 miles. This will flush out any build-up and clean the injectors, improving your gas mileage, saving money on fuel costs, reducing emissions, protecting and restoring the performance of your car, and increasing engine life and performance.

There are two methods for cleaning your fuel injectors: using a fuel injector cleaner and a fuel injector cleaning kit.

The first method is to use an over-the-counter fuel injector cleaner to flush out your injectors. These cleaners contain detergents that can break down gunk and are applied directly to the fuel tank, allowing them to run through the injectors along with the fuel. This method is good for preventative maintenance but may not be effective for heavily clogged injectors.

The second method is more complex and involves hooking up a pressurized fuel cleaner to the engine's fuel rail. This process requires a fuel injector cleaning kit, a wrench/socket set, an air compressor, and safety gear such as gloves and safety glasses. Here are the steps to follow:

• Fill up the canister from the cleaning kit with the recommended cleaner and screw the lid back on.
• Hang the canister from the underside of the hood, above the engine.
• Pull the fuel pump relay to prevent the fuel pump from running during the procedure.
• Attach the canister to the fuel rail test port.
• Attach the air compressor hose to the canister's air port.
• Adjust the pressure on the canister's gauge as directed by the instructions, typically a few pounds lower than the car's normal fuel rail pressure.
• Start the car and let it run until all the solution in the canister has flown through the fuel rail, which can take up to 10 minutes.
• Stop the car and disconnect the air hose and canister hose from the fuel rail.
• Reconnect the fuel pump relay in the fuse box to start the car again.

In addition to regular cleaning, there are a few other tips to keep in mind for fuel injector maintenance:

• Use high-quality, OEM parts when replacing fuel injectors to ensure even power across the engine and a proper air-fuel mixture for all cylinders.
• Always disconnect the battery and take proper precautions against fire when working with fuel.
• Fuel injector replacement is a complex task that should be left to a professional to avoid the risk of fire and further damage to the vehicle.
• Before cleaning the fuel injectors, check the air and fuel filters, as they are typically much easier to service and can also cause similar issues to clogged injectors.

By following these maintenance tips and keeping your fuel injectors clean, you can help ensure the optimal performance and longevity of your vehicle.

Fuel injector replacement safety

Fuel injectors are an essential component of modern vehicles, but they require careful handling to avoid safety issues. Here are some key considerations for fuel injector replacement safety:

Risk of Fire: Working with fuel injectors involves handling flammable fuel, which poses a fire risk. It is crucial to disconnect the battery before starting work to minimise the risk of sparks or electrical issues that could cause a fire. Taking this precaution is essential for safety.

Complexity of the Task: Replacing fuel injectors is a complex and technical task that requires a good understanding of engines and their components. Incorrect removal or installation can lead to further damage to the vehicle. It is recommended that fuel injector replacement be left to trained professionals to avoid accidental damage.

Engine Cooling System: The engine cooling system, which helps maintain optimal temperatures during operation, can pose a safety hazard if not handled properly. When removing fuel injectors, it is important to isolate the engine cooling system to prevent the escape of high-temperature water under pressure. This precaution helps reduce the risk of scalding or burns to the person performing the maintenance.

Personal Protective Equipment (PPE): When working on fuel injectors, it is essential to wear appropriate PPE to protect against potential hazards. Safety glasses, long rubber gloves, and boots are recommended to shield the eyes, skin, and body from any escaping fluids or debris.

Manufacturer's Instructions: Referring to the vehicle manufacturer's instructions is crucial for safety. These instructions are designed with safety in mind for both the technician and the vehicle. Following the recommended procedures can help prevent accidents and ensure the correct tools and techniques are used.

Risk Assessment: Conducting a thorough risk assessment before starting any maintenance work is vital. This assessment helps identify potential hazards and allows for the implementation of control measures to minimise risks. It ensures that the technician is prepared for any challenges and has the necessary knowledge, equipment, and support to complete the task safely.

By following these safety guidelines, technicians can help ensure that fuel injector replacement is carried out without causing harm to themselves, the vehicle, or those around them.

Fuel injector replacement procedure

Overview

Before starting, it is important to note that fuel injector replacement is not a beginner-friendly repair job and is best left to a professional. It involves working with gasoline, which poses a risk of gas leaks or fires if done incorrectly.

Preparation

Start with a cold car and disconnect the battery to ensure that the fuel injectors are not firing during the replacement process. Let the car cool off for 30-45 minutes if it has been driven recently. Put on gloves and remove the battery terminals.

Locate the fuel injectors on the intake manifold, which is behind or above the engine, with 4-8 pipes leading into the engine. The fuel injectors are the connectors that run from the fuel rail into these pipes.

Removing the Old Injectors

Use pliers to remove the fuel injector connectors on the fuel rail. Depending on the vehicle, a screwdriver or wrench may be needed to unlock the connectors first. If necessary, relieve the pressure in the fuel line by holding a rag over an air valve or unscrewing the fuel line with a socket wrench.

Unlock and remove the fuel rail using a socket wrench or screwdriver. There may be clips, screws, or bolts holding it in place. Gently pull the railing up and away from the engine, placing a rag underneath to catch any gasoline droplets.

Gently wiggle and pry the individual injectors out of the fuel rail by hand. Take a quick photo of the injectors to remember their orientation and direction for installing the new ones.

Installing the New Injectors

Purchase new injectors designed for your specific engine. Dip the tip of each injector into a small cup of gasoline to lubricate the O-rings and prevent gas leaks.

Slide the new injectors into their slots on the fuel rail, inserting the end with the clips first and ensuring the gas-dipped side is facing the engine's intake manifold.

Line up the injectors with the corresponding holes on the engine and carefully slide them into their slots. Reattach any connectors, clips, or covers that were removed earlier.

Restarting the Vehicle

Turn the key to the "on" position to prepare the vehicle's starter and fill the fuel rails with gasoline, but do not start the engine yet. Wait for 20-30 seconds, then start the engine and let it run for a minute.

Inspect the engine for leaks by turning off the vehicle and using a flashlight to check the fuel rail and under the car for any signs of leakage. If leaks are present, confirm that the injectors are inserted correctly into the manifold. Do not continue driving if leaks cannot be fixed.

Additional Notes

It is recommended to change all fuel injectors as a set, even if only one or two need replacing, to ensure an equal amount of gas reaches each cylinder.

The cost of fuel injector replacement, including parts and labor, can vary from $500 to $2,500, depending on the vehicle.

Frequently asked questions