What are fuel injectors?
A fuel injector is the part of an engine’s fuel delivery system that receives and sprays gasoline (or diesel) into the engine in the form of a high-pressure mist. Fuel injectors are controlled by the engine computer to optimize the amount of fuel as well as the timing of the fuel injection. There is one injector per cylinder that delivers fuel to the engine.
Do different cars have different types?
In a traditional fuel injector setup, the injector sprays fuel into the intake manifold, where it mixes with air before entering the combustion chamber where the mixture can be ignited. In recent years, more manufacturers have made the switch to direct injection, a system in which the fuel injector sprays gas directly into the cylinder, instead of into the intake. This system allows for higher fuel efficiency and better emissions control as well as higher power output from smaller engines.
Why do they fail?
Fuel injectors are not wear items and can even last the life of the vehicle. However, as with every mechanical part, there are issues that can and do occur. Fuel injectors can fail from contaminants (such as dirt, carbon buildup, or low-quality fuel) clogging the injector. Sometimes they can be cleaned, but they often require replacement. A fuel injector can leak due to aging of its rubber seals, or it can leak from cracks in the injector itself. If the seals are the culprit, they can usually be replaced on their own. However, the only remedy for a cracked injector is complete replacement. The electrical components of an injector can also fail from age, heat, and moisture damage.
How will I know if I have a problem with my fuel injectors?
A faulty or clogged fuel injector will cause an engine to misfire because one or more of the cylinders is not receiving the fuel it needs to run properly. These misfires are usually felt as a rough idle or lack of power and may go hand in hand with a check engine light. If a fuel injector is still spraying and working properly but is leaking, there will likely be a fuel smell present while the vehicle is running.
What if I don’t fix them?
A leaking fuel injector is a definite safety concern, as the leaking fuel and vapors can ignite under the hood and cause a fast-spreading fire. An injector that is clogged or stops working is not a fire risk, but will cause the vehicle run poorly. Additionally, it can lead to internal engine damage from fuel starvation and increased temperatures stemming. By addressing fuel injector issues when they arise, hazards and costly repair bills may be prevented.
What do they cost, and why?
Replacement of a single fuel injector on a more simple engine may cost as little as $200. However, many newer vehicles have more complicated or high-tech fuel delivery systems and therefore a higher cost of parts and labor. Other cars may have fuel rails (which hold the injectors) that are difficult to access. In some cases, a single injector can cost several hundred dollars or more to replace.
Is there anything I should replace at the same time?
If a fuel injector is found to be faulty, it is usually recommended to replace all of the injectors based on the age, condition, and/or contaminants in the fuel as there is not much difference in the amount of time required. When replacing injectors, it is also necessary to replace the small rubber o-ring seals that seal the injector and prevent fuel vapors from escaping. If the seals are not replaced, fuel leaks may present themselves soon after the repairs are completed.
Is there anything I can do to lower the cost of repair?
One of the most important things that can help prevent premature fuel injector failure is proper fuel system maintenance. Manufacturers often specify a time or mileage interval for fuel filter replacement, so be sure to check and follow the recommendations for your vehicle to help reduce the amount of contaminants reaching the fuel injectors. Other preventative measures include using high quality fuel and adding a fuel injector cleaning additive to the gas tank approximately every 5000 miles or as specified by the manufacturer. If repairs are needed, aftermarket or remanufactured parts may be available, but the service life or quality of those parts may be reduced when compared to the original equipment.