Replacing The Fuel Injector In Your Montero: Step-By-Step Guide

The Mitsubishi Montero is a rugged and solid vehicle designed for excellent off-road performance. Its engine relies on fuel injectors, which spray atomized droplets of fuel into the engine's intake manifold or combustion chamber. Over time, these fuel injectors can become clogged, dirty, or unresponsive, leading to a range of issues that impact the drivability of the vehicle. This includes problems such as misfiring cylinders, a vibrating engine, poor fuel economy, and difficulty starting the engine. In some cases, a leaking fuel injector can cause a strong fuel odour or even engine stalling. To replace the fuel injectors in a Mitsubishi Montero, it is recommended to seek a certified mechanic as it is not a DIY job due to the risk of fire and the complexity of the process. The average cost for this replacement ranges from $1010 to $4362.60, depending on the model year and labour costs.

Rough idle, loss of power, or misfiring

A rough idle, loss of power, or misfiring could be signs that your Mitsubishi Montero's fuel injectors need replacing. Fuel injectors are fuel metering devices that spray atomized droplets of fuel into the engine's intake manifold or directly into the combustion chamber. When they become clogged, dirty, or unresponsive, not enough fuel enters the combustion chamber, leading to engine problems.

To replace the fuel injectors in your Mitsubishi Montero, you will need to relieve the pressure in the fuel rail by briefly running the engine with the fuel pump fuse removed. Once the engine is cold, remove the upper plenum on the intake manifold, along with any cables, hoses, or wiring that may restrict access. Then, carefully remove the supply and return lines from the fuel rail, followed by the electrical connectors to each fuel injector. The fuel rail can then be unbolted and removed from the intake manifold.

Next, take out the faulty injector(s) from the fuel rail, being careful not to let any debris enter the exposed openings. Fuel injectors are usually held in place by an O-ring seal, which fits very tightly to prevent fuel leaks. Install a new O-ring onto the replacement injector and insert it into the fuel rail, using engine oil to prevent damage to the O-ring. Reinstall the fuel rail, reconnect the supply and return lines, and remount the plenum along with all cables, hoses, or wiring. Finally, start the engine and carefully check for leaks.

It is important to note that fuel injectors are precision components, and even a single faulty injector can cause a noticeable decrease in performance. Therefore, it is recommended to service or replace all injectors at the same time to ensure balanced flow rates and smooth engine operation.

Odor of raw gas or visible leaks

If you notice an odor of raw gas or visible leaks around your Mitsubishi Montero, it is important to act promptly to prevent potential safety hazards and costly repairs. Here are some detailed steps to identify and address the issue:

Identifying the Issue

When dealing with fuel leaks, it is crucial to work with caution and prioritize safety. If you suspect a leaking fuel injector, refrain from starting your vehicle as it may pose a fire hazard. The following steps can help you identify a faulty fuel injector:

• Check for any fuel odor around your car. Fuel injectors should not leak fuel into the intake manifold when the car is off, so any unusual smell could be indicative of a problem.
• Inspect for visible leaks. Look for fuel puddles underneath the car or signs of fuel leakage around the fuel injectors and fuel lines.
• Observe the engine's behavior. Issues with fuel injectors can lead to rough idle, loss of power, or misfiring.
• Check the check engine light. A faulty solenoid in the fuel injector may trigger a trouble code, causing the check engine light to illuminate.

Immediate Action

Once you have identified or suspected a leaking fuel injector, it is important to take immediate action to ensure safety and prevent further complications:

• Ensure proper ventilation in the area to avoid the risk of exposure to fuel fumes.
• Do not start your vehicle if you suspect a leaking fuel injector. This could create a fire hazard.
• Contact a qualified mechanic as soon as possible to inspect and repair the issue.

Long-Term Solutions

To address the issue of a leaking fuel injector in your Mitsubishi Montero, consider the following long-term solutions:

• Fuel injector replacement: In some cases, it may be necessary to replace the faulty fuel injector with a new one. This can be done by removing the injector from the fuel rail, taking care not to damage the O-ring seal, and installing a new injector with a new O-ring.
• Fuel injector cleaning and servicing: In certain situations, it may be possible to service and clean the fuel injectors instead of replacing them. This typically involves removing the injectors from the car and using specialized cleaning and test equipment.
• Regular maintenance: Preventive measures are crucial to maintaining a healthy fuel system. This includes using high-quality fuel, utilizing fuel additives to maintain injector cleanliness, and adhering to a regular servicing schedule.

Remember, addressing fuel injector issues promptly is essential to ensure the safety and optimal performance of your Mitsubishi Montero. Do not ignore the issue, as it could lead to severe consequences, including engine damage, increased emissions, and potential fire hazards.

Check engine light

The "Check Engine Light" is a warning light that alerts the driver about any type of engine problem. The light comes in two colours: yellow to indicate minor problems and red to indicate serious problems.

If the check engine light is blinking continuously, it indicates a critical problem and you should stop driving your vehicle. A steady light, on the other hand, indicates a non-emergency situation and you can continue driving but should schedule an appointment with a mechanic as soon as possible.

The check engine light can be caused by a number of issues, some more serious than others. Here are some of the most common reasons for the check engine light to come on:

• Loose or damaged gas cap: The gas cap acts as a seal for your fuel system and helps maintain the pressure in your fuel tank. A loose or damaged cap can reduce your gas mileage and increase emissions from your car.
• Faulty oxygen sensor: An oxygen sensor monitors the exhaust for unburned oxygen, which indicates engine efficacy and the proper air-to-fuel ratio. If you have a faulty sensor, it will not provide the correct data to the onboard computer.
• Failing catalytic converter: A catalytic converter helps reduce emissions in exhaust gases by converting harmful gases into less harmful emissions. A failing converter will negatively affect your gas mileage and, when the damage becomes severe enough, your vehicle won’t go any faster when you push down harder on the gas pedal.
• Faulty mass airflow sensor: This part directs the computer in your vehicle to add the correct amount of fuel based on the air that is coming through the engine. When a mass airflow sensor starts to fail, the car will stall, idle poorly, emissions will go up, and your gas mileage will decrease.
• Bad spark plugs and wires: Spark plugs act as a seal in the combustion chamber and provide the gap for the spark that causes combustion in the engine.

If the check engine light comes on, a mechanic will use a scanner to read the "fault codes" and diagnose the problem. The mechanic will then quote the necessary repairs and, if approved, will replace the faulty parts and clear the memory of any fault codes.

Major engine repairs, engine replacement, or lengthy storage

When an engine is disassembled or if a new engine is being installed, it is the perfect time to service the injectors as a set. All injectors have tiny internal filter baskets that can be cleaned ultrasonically by a professional injector service facility. This service is relatively low-cost and will ensure the injectors are balanced in terms of flow rates, promoting the smooth operation of the engine.

If an injector problem has developed that requires the removal of one injector, it is best practice to remove and service all of the injectors simultaneously. This service may involve the replacement of the electrically failed injector, along with the off-the-car cleaning of the remaining injectors. Serving all injectors at once ensures the injector set will be balanced.

On-car cleaning of fuel injectors is not as effective as off-the-car cleaning because injectors have tiny internal filter baskets that should be replaced as part of the process of servicing a fuel injector.

When replacing a fuel injector, it is important to use high-quality (Tier One) gasoline to reduce deposits and prolong the life of the fuel injectors. Additionally, do not use fuel system cleaning compounds or procedures unless they are specified by the manufacturer of your car.

Fuel injector replacement cost

The cost of replacing a fuel injector will depend on a number of factors, including the type of vehicle, the brand of fuel injector, and the location of the repair. On average, the cost of replacing a fuel injector can range from $300 to $900, with some estimates giving a broader range of $500 to $2,500. The cost of parts and labour can be between $150 and $400.

The price of individual fuel injectors can vary, with some costing under $40 each, while others are several hundred dollars apiece. The number of injectors that need replacing will also impact the overall cost.

Factors Affecting Cost

The type and make of your vehicle, as well as its age, can play a significant role in determining the cost of replacement. The quality of parts used and the labour rates of the mechanic will also influence the final price.

Signs of a Bad Fuel Injector

• Increased fuel consumption
• Decreased engine performance
• Engine misfires
• Rough idling or stalling
• Fuel leaks
• Check engine light

When to Replace a Fuel Injector

Fuel injectors typically last between 50,000 and 150,000 miles, but they will eventually need to be replaced due to wear and tear, or clogging. Regular maintenance and cleaning can help prolong their lifespan.

Saving Money on Fuel Injector Replacement

To save money on fuel injector replacement, you can compare prices and shop around for the best deal. Purchasing refurbished or remanufactured fuel injectors is also an option, as they can be more affordable than brand new ones.

DIY vs Professional Replacement

Replacing a fuel injector requires precise knowledge and experience, so it may be best left to a professional mechanic. Improper installation can lead to bigger and more expensive problems down the road.

Frequently asked questions