Basics Of Replacing Your Timing Belt

There are a lot of circumstances – and not all of them are car-related – that can potentially prevent you from getting to work in the morning. Your car’s timing belt is one of them. Most people have heard of them, but are still not entirely clear what they’re for or what they do. Frankly, they’re just glad to have a mechanic who knows what they’re doing when replacing it.

Essentially, this part plays a critical role in the management of the cylinders inside your car’s engine and at what rate those cylinders are ignited. Without this crucial functionality, your engine simply cannot run. That’s the main reason why you need to periodically inspect it to make sure it’s in good working condition.

Does it Need to be Replaced?

The easiest way to verify whether or not you’re due for a replacement is to check your car’s owners manual. (If you’ve been reading my articles, you’ll know that I keep pressing this point.) Depending on your car’s make and model, a different mileage point will be suggested at which you should have your timing belt replaced (or, at least inspected).

That interval is typically between 60,000 and 90,000 miles, but it can be less or more in some cases. If you don’t have access to your owners manual, you can either try to locate the information online, or simply visit to your local auto parts retailer and they should be able to tell you. They’ll have large reference manuals in which they can find the information.

Often, a lot of drivers make the mistake of assuming that since their timing belt is “squeaking” that it needs to be replaced. Despite what your mechanic may tell you, that’s not always the case. It’s not uncommon for it to make a bit of noise in very cold conditions, or in older vehicles. However, if you’re concerned, consider visiting your mechanic. He can usually tell very quickly just from looking at the part whether it needs to be replaced.

The Cost of Replacement

If it turns out that you do need to have the timing belt replaced, expect to pay approximately $30 to $40 for the part itself. That’s only an estimate; the price will vary slightly based upon the type of vehicle you’re driving. Also, it’s likely that you’ll end up paying approximately $100 to $150 for the labor involved. Ultimately, budget about $200 total to have the work performed.

Your car’s timing belt will eventually need to be replaced. The bottom line is that you should always check your owners manual. And when you have a few minutes, pop the hood and inspect the belt yourself.

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.

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