A fuel injector is an electronically-controlled valve that sprays gasoline into an inlet manifold or directly into an engine. As it contains both mechanical and electrical parts, it may fail both mechanically and electronically. Its failure to operate properly may lead to many engine troubles, including the following:
Reduced performance and a loss of power
A typical engine is equipped with one fuel injector per cylinder, so most likely it will not shut down if one of the injectors fails. However, since the combustion process in the cylinder with a failed injector will not occur due to the lack of fuel, the engine will misfire, resulting in poor performance and rough idling. If so, you’ll feel excessive vibration, hesitation and inability to speed up as it used to happen.
Check engine light on your dashboard is on
The operation of the fuel injectors is monitored by the engine control unit. Once it detects a misfire, the computer will turn the check engine light. As soon as you notice the check engine light is on, you should go to a safe spot and stop the engine as its further operation may destroy your catalytic converter. The other bad news is that you will not pass the emissions test until the problem is fixed.
Rough idling and a hard start
Your fuel injectors are properly sealed to prevent any kind of leaking. However, if the sealing wears out or gets damaged, some fuel will leak into the cylinder, making the air/fuel mixture too rich to keep the combustion process running. It is especially noticeable after long breaks, for example, in the morning when you turn the ignition key to start the engine, but it doesn’t start since one or more cylinders contain excessive fuel. In this case, your starter has to crank the engine longer until it starts. This problem cannot be ignored as it may ruin your cylinders.
Increased fuel consumption
Thanks to a special nozzle in a fuel injector, it anatomizes petrol when spraying it into the intake manifold or cylinder. A clogged or dirty nozzle cannot ensure a fine mist of fuel, making the combustion process inefficient since a lot of fuel is wasted.
Black smoke and foul odors from the exhaust
The engine control module calculates the amount of fuel that needs to be sprayed into cylinders based on the fact that all injector are in mint condition. A faulty injector may cause the engine running too rich, so excessive fuel will leave the motor, causing black smoke and foul odors.
On some occasions, an injector body or o-ring may fail, resulting in fuel leaks. If this happens, you will feel the smell of raw fuel. You should not start the engine as it can be dangerous and cause a fire. Instead, you should get in touch with your mechanic.
What is a fuel injector?
The times when cars and trucks with inefficient carburetors where the kings of the road have been long over. Today’s vehicles rely on computer-controlled fuel injection systems that provide better fuel efficiency and lower emissions.
The key component of any fuel injection system is a fuel injector, which is a quite simple and reliable device, but like any mechanical part, it is also prone to wear and tear.
By design, a fuel injector is a computer-controlled valve that can open multiple times per second during engine operation. When it’s open, pressurized fuel is forced through its nozzle into the intake manifold or cylinder.
As a rule, most engines come with one fuel injector per cylinder, which is controlled by the engine’s computer. All injection systems can be divided into two main categories, including port fuel injection and direct fuel injection. The main difference between these systems is the location of fuel injectors. In port fuel injection systems injectors mount into an intake manifold, while direct injection systems feature injectors installed into a cylinder head and spaying fuel directly into cylinders to reduce fuel consumption and improve emissions.
Are fuel injectors repairable?
Most fuel injectors are very reliable and do not require any kind of special service. However, if it fails, complete diagnostics of the fuel injection system at a repair shop is a must to fix the problem. Sometimes problems with other engine systems, for example, an ignition system, may be misinterpreted as signs of a bad injector.
To determine the root of the problem, a technician will not only need to check the injectors, but also to test the electrical wiring and the engine control unit, and, sometimes, even provide some leak tests. In some cases, you will need to replace all injectors if they are totally worn out.
The repair cost varies depending on the type of injection system and the complexity of the problem. The replacement job is usually not very expensive when it comes to a typical engine. However, high-performance engines with direct fuel injection are much more complex, which automatically multiplies the cost of repair parts and labor.
Should I clean my fuel injectors?
While many repair shops recommend fuel injector cleaning as a basic maintenance option, the efficiency of this procedure is debatable. It will not help you to fix the problem if an injector is worn out or damaged. However, since this doesn’t require removal of your fuel injectors, you may try this option before replacing them.
Today, you may also find a variety of fuel injector cleaners, so you can use them as an alternative to fuel injection cleaning at a repair shop.
Some engines come equipped with hard-to-find or very expensive fuel injectors. If this is also your story, you may try to rebuild your injectors. In this case, the removal of fuel injectors and their delivery to a repair shop is required. This is a time-consuming process that involves more labor and expense.
Can I replace or repair a fuel injector myself?
Unless you are a professional mechanic, fuel injector replacements and repairs are something that we do not recommend you to do yourself. It is a complex process that requires special tools and involves a lot of labor to take off all needed parts. A lack of experience working on fuel injection systems may lead to occasional engine damage or injury.
Port fuel injection systems are easier to inspect and repair. A poor fuel injector should be replaced with a manufacturer-recommended part using proper tools and following the manufacturer’s recommendations. The o-rings should also be replaced on both ends of your injectors.
Direct ignition systems need much more accuracy and attention compared to their counterparts as their components are subject to higher pressure.