Guide To Your Vehicle’s Fuel Injection System

In 1990, the last model to roll out of the factory with a carburetor installed was the Subaru Justy. Since then, all cars have been designed with fuel injection systems (FIS). While carburetors were an impressive piece of machinery, they could not keep pace with the rapid evolution of automotive engines. Moreover, as emission standards rose, catalytic converters were installed into vehicles to reduce the harmful gases present in the exhaust. Because catalytic converters require a precise air-fuel mixture in order to do their job, the carburetor’s days were numbered.

Today, fuel injection systems carefully control the amount of gasoline that enters the combustion chamber of each cylinder. Below, you’ll learn how your vehicle’s FIS works and the process by which fuel is metered and controlled.

Basics Behind The System’s Operation

When you press down on your accelerator, a throttle valve opens and allows air to flow in toward the cylinders. Your vehicle’s computer (called the engine control unit, or ECU) takes note of the open throttle valve and sends fuel toward the injectors. This happens almost instantly to ensure the right air-fuel blend ends up inside the combustion chambers.

Each injector is a valve that opens to allow gasoline to shoot directly through the intake valve into its corresponding combustion chamber. It opens and closes quickly based on instructions received from the ECU. When the fuel flows through the injector, it comes out as a mist in order to burn more cleanly. The amount of fuel sent into the chamber is regulated by the amount of time the valve remains open. This period is called the pulse width.

How The Amount Of Gasoline Is Metered

Because the ECU is responsible for sending pulse width directions to the injectors, it must have a way to monitor the amount of fuel needed for specific driving conditions. It uses data from several sensors.

Oxygen sensors monitor the level of oxygen present in the exhaust coming from the combustion chambers. This data helps the engine control unit to identify a too-lean or too-rich mix and make the appropriate adjustments. An engine speed sensor is used by the ECU to regulate the injectors’ pulse width. A mass airflow sensor sends data to the ECU regarding the amount of air coming into the engine.

Other sensors monitor the throttle position, voltage level, operating temperature, and how much pressure exists in the intake manifold. All of this data is used to carefully meter the amount of fuel that flows through the injectors.

Your fuel injection system can develop a number of problems that will affect your engine’s performance. For example, your injectors can clog. Or, one or more sensors might fail, leading to a too-lean or too-rich air-fuel mix. These issues (and others) can cause a hard start, misfire, hesitation, or stall. If you notice any of these problems, visit a repair shop to have your car’s fuel injection system tested. Otherwise, you might eventually find yourself stranded at the side of the road.

How To Select An Extended Warranty

All new vehicles come with a warranty. Automakers realize that some of their cars, trucks, and SUVs will develop problems far sooner than they should. When a particular part or system fails, the cost of having it repaired is covered for the owner. Of course, warranties do not last forever. When they expire, the owner is left to pay for the cost of repairs and replacement parts. Because both can be expensive, many companies offer extended warranties to drivers. The extra coverage allows motorists to hedge their bets. By investing upfront, he or she can partially shield themselves from the high cost of various types of automotive services.

Below, we’ll explore extended warranties in more detail. I’ll explain a few of the most important factors to consider when choosing a service contract.

What Is Your Current Coverage?

Your decision to invest in extra coverage will depend heavily upon your current factory warranty, your driving habits, and how long you intend to keep your vehicle. For example, suppose that your factory warranty covers your entire car for three years or 36,000 miles. Further suppose that you plan to drive 12,000 miles each year and trade it in after three years. In that case, investing in an extra service contract would be a waste of money. You won’t be able to make use of it.

On the other hand, if you plan to keep your vehicle for ten years and you expect your annual mileage to climb past 12,000, an extended warranty may be a good idea.

Consider The Deductible

Deductibles can be confusing. Most extended warranties have a deductible that you’ll need to pay before the coverage becomes active. However, service contract companies handle it differently. Some will put the deductible on a “per visit” basis. Others will carry it for each individual repair. That might seem like a negligible detail, but it can add up to hundreds of dollars.

For example, suppose you’re taking your SUV to the dealer to have your water pump, alternator, and catalytic converter replaced. If the deductible is $125 and is carried for each individual repair, you’ll need to pay $375 before your coverage starts. On a “per visit” basis, your deductible would only be $125.

Review The Details Beneath The Surface

Extended warranty contracts contain dozens of small details that are easy to miss. Some require that all work is done by dealership technicians while others let you choose from a number of repair facilities. Some allow you to transfer the service contract to a new owner in the event you sell your vehicle; others don’t. Some require that you pay for repairs upfront and forward the receipt for reimbursement. Take the time to carefully read through the contract.

Investing in an extended warranty can be a fantastic way to mitigate the high cost of auto repairs and OEM replacement parts. But, keep in mind that each policy is different and requires a thorough review.

« Older Posts — Newer Posts »