One of the things that make a car fuel-efficient is the fuel injector. It gives the engine the exact amount of gasoline needed for internal combustion. It is also essential in the motor’s gasoline delivery system.
As soon as the car starts, the fuel injector immediately works to provide the engine with the power it needs to perform.
Cost of Fuel Injectors – Parts and Services
The cost to replace fuel injectors depends on the vehicle type, its model, and the labor fee. The average price of fuel injector replacement can range from as low as $50 up to as high as $3,000 or more. Some are just for parts only while some include labor.
Labor fee is estimated between $88 and $311. As for the parts, the cheapest and simplest type of fuel injector may cost as low as $25. If you opt for better brands, some fuel injectors may go over $1,000.
A little expensive? Don’t worry though, fuel injectors rarely need to be replaced unless it is really damaged. Most injectors just need cleaning from time to time.
Below are some of the chains that offer fuel system services that include fuel injector cleaning. It may be higher if you include fuel injector replacement. Chains like Goodyear, Firestone, Jiffy Lube, Mr. Tire, and Valvoline also offer this service.
You can check out their websites to get a quote for your car as well as discounts.
|Shop||Price Range (Service, Replacement, Labor)|
|Midas||Starts at $105|
|Sears||Starts at $85|
|Pep Boys||*$9 – $99|
|Your Mechanic||$90 – $2,500|
What Does A Fuel Injector Do?
The fuel injectors basically control the vehicle’s fuel consumption. Without them, fuel won’t be delivered to the engine in proper amount.
It functions by converting the fuel into a fine mist. The engine can burn it more evenly and efficiently since mist can burn easily compared to a solid stream of gas.
The amount of fuel being released to the engine’s cylinders depends on how long the fuel injector is open – also known as the Pulse Width. It is then managed by the vehicle’s engine control unit or ECU which collects information about the engine conditions and requirements using different internal sensors.
If a fuel injector functions correctly, it will disperse the fuel at the right angle, pressure and spray pattern. This means less fuel is wasted and also fewer trips to the gas station.
On the other hand, if one of your fuel injectors is damaged, the cylinder that it’s supposed to be powering will not function properly. In turn, your vehicle will not run smoothly and will have a great chance to misfire.
When Should You Replace Your Fuel Injector?
Fuel injectors usually can last between 50,000 – 100,000 miles. It depends on the gas used and also the fuel filter. As mentioned earlier, it isn’t that necessary to change the injector. Some just need a little cleaning.
Newer vehicles that have newer design are less likely to need fuel injectors cleaning compared to older ones. The additives in most fuels that prevent the formation of certain particles that usually clog injectors help too.
Using fuel injector cleaners from time to time can also lengthen your injector’s life. One of the most trusted brands by automakers when it comes to fuel system cleaners is Techron from Chevron. It’s usually used at least every 4,000 miles or so.
However, when you notice certain problems like significant lower mileage, difficulty in starting the engine, and smelling fuel, then you might need to check your injectors. Your trusted mechanic will know whether you need an injector replacement or just an injector cleaning.
Always remember that clean injectors are vital for engine function and efficiency. When dirty or faulty injectors are cleaned or replaced, you can see noticeable results with the engine’s performance.
Types of Fuel Injection Systems
Fuel injection in cars has developed over time and there are different schemes that are produced. They are either controlled mechanically or electronically.
In a mechanical injection, the injector is spring-loaded into the closed position and is opened by fuel pressure. Most drag racers prefer this since fuel is given at one go. Meanwhile, in an electronic injection, the ECU determines how long the injector stays open.
Injectors may also be classified as either top-feed where the fuel enters from the top and exits the bottom; or side-feed where fuel enters on the side of the injector fitting inside the fuel rail.
Below are the 4 types of injectors used in newer cars.
- Throttle body injectors or Single Point Injectors
Before the other systems were developed, throttle body injectors were first used. It is the earliest and the most basic type after the carburetors. It functions more like a computerized carburetor but it meters fuel better.
Since this was considered the stepping stone to the more complex multipoint system, it is not as precise as its successors. It only has one injector that delivers fuel to the engine and because of that, not all fuel may enter the cylinders. It is located on top of the engine and has one or two fuel-injector nozzles in the throttle body or the throat of the engine’s air intake manifold.
Throttle body injector works by supplying the correct amount of fuel to the air before it is delivered to the individual cylinders. This injector is less expensive than the others. It also has a fairly high flow rate which means it’s not as easy to clog up and therefore easier to maintain.
- Port or multi-point fuel injection (MPFI)
This system is sometimes called the port injection. It designates a separate injector further down towards each engine cylinder, right outside its intake port. Since it delivers fuel vapor this close to the intake port, there is a lesser possibility for the fuel to condense in the intake manifold.
MPFIs are highly efficient in metering gas into the engine because they ensure that fuel will be drawn completely into the cylinder. Simultaneously spraying fuel into the cylinders will result in better fuel delivery.
Compared to the Throttle Body Injector, they meter fuel more precisely by achieving the desired air to fuel ratio. Engines with MPFI can have intake manifolds made from light-weight materials. They can also be placed in a different place instead on the top of the engine.
One downside of these injectors is that they all spray simultaneously while the cylinders fire one after the other – sometimes even before the injector has a chance to deliver additional fuel. This results in having more leftover fuel between in-take periods. They also cost more than the TBI but for the price, they offer more power and greater fuel economy.
- Sequential fuel injection (SFI)
SFI is a type of multi-port injection. It works very similarly with the MPI; the only difference is that this system is timed. It is also the most advanced and offers the most precise fuel delivery.
It works by triggering each injector nozzle independently. Instead of all injectors firing at the same time like in MPI, it delivers fuel one after the other and in time with the cylinders. This allows the engine to mix the fuel right before the intake valve opens.
This system offers a quicker response, better fuel economy, and performance. Since fuel doesn’t stay on the port for a long time, this injector tends to last longer and remains cleaner than other systems.
The weakness of this system comes from its strength. It is meticulous to maintain and should have less room for error because the fuel and air mixture is sucked into the cylinder only moments after the injector opens. It means that if it is dirty and clogged, it might not do its job properly. The fuel injector price of this kind can also be a little more expensive.
- Direct injection
Sometimes called DIG or Direct Injection Gasoline, this system has been used not only in diesel cars but also in aircraft engines since the World War 2.
It works by delivering the fuel directly into the combustion chambers and past the intake valves. Therefore, it offers a more complete combustion. It also produces cooler cylinder temperatures that result in a higher compression ratio for greater efficiency and power.
It is commonly used in diesel engines because the fuel is so much thicker and heavier. Compared to other systems, it offers more precise fuel metering.
Most performance vehicles use this system since its fuel delivery can take a lot of abuse and have fewer maintenance issues. Even if that’s the case, it’s also important to maintain your fuel delivery system so you can prevent future injector problems.
Common Causes of Fuel Injector Failure
Fuel injectors fail because of natural wear or external reasons. Knowing the common causes of the injector’s failure can help you prevent any problems that may arise in the future.
One of the most common causes is the heat soak. When the engine is not running, the cooling stops from all sources. The injector starts to evaporate the remaining fuel on the nozzle due to the increase in temperature and lack of airflow.
In turn, varnish is produced and begins to build up and obstructs the flow of fuel. To prevent this from happening, a fuel injector cleaner is usually added to the fuel. But once the injector is already clogged, the cleaner won’t work anymore and you might need to have your nozzles cleaned professionally.
Usually, the middle injectors are the ones more prone to clogging because the middle cylinders are the warmest parts after the engine shuts down.
Another common cause of injector failure is internal shorts. When this happens, the resistance will drop and will then cause the injector to need more amperage to function. In some vehicles, this will make the ECU shut the injector down.
Next is water in the fuel. Water doesn’t have any lubricating properties so once the fuel is contaminated with water, it will damage the injectors. The ideal water content in fuel is under .05 percent by volume. Anything more than that will affect the fuel injectors since water just vaporizes and turns to steam when in contact with the system.