Fuel Injectors: Potential Problems That Can Affect Their Operation


There are many factors that influence the performance of your vehicle’s engine. For example, the oxygen sensors, valves, head gasket, and myriad other components must be working properly if your engine is to perform efficiently. Having said that, many of the engine-related problems that plague drivers are due to their fuel injectors (FIs). They become dirty over time. When that happens, you might experience a decline in the performance and efficiency of your engine.

Below, we’ll take a closer look at the effects a dirty FI can have on your car. I’ll describe what happens when clogs develop and describe the factors that contribute to obstructions.

When Fuel Injectors Become Clogged

If you have ever seen an FI up close, you’ll already know that a small obstruction can cause the air-fuel mixture to lean out. A lot of drivers mistakenly think a significant blockage is necessary in order to affect an injector’s operation. In reality, the blockage may represent no more than ten percent of the nozzle’s opening. Even that can potentially lead to misfiring. As a result, excess oxygen leaves the cylinder and flows into the exhaust system. The oxygen sensor takes note of the excess and reports the lean mix to the computer.

Within the closed feedback loop, the computer will adjust to the lean mixture by sending more fuel to the injectors. Unfortunately, this does not resolve the underlying problem. The issue is made worse by an altered spray pattern. If the spray pattern is affected due to a clog, the fuel will burn less efficiently in the combustion chamber.

The Root Cause Of Clogging

Even though most modern FIs are designed to resist clogging, it happens frequently. The reason is due to the gasoline that flows through the system. The gasoline you buy at the pump is filled with hydrocarbons. Within the hydrocarbons, there are olefins, a waxy substance that contributes to deposits that accumulate and clog the FIs.

When you turn your car off, the fuel injectors remain extremely hot. The heat causes any residual gasoline still within the nozzles to vaporize. Unfortunately, the olefins are left behind. They harden into deposits and over thousands of miles, begin to form an obstruction in the nozzles. The problem occurs so gradually that drivers seldom realize it’s happening.

Gasoline contains special detergents and additives that are designed to keep the fuel injectors clean. However, low-cost suppliers often reduce the level of these elements in order to cut costs and preserve their profit margin. The irony is that many people buy low-priced gas to save a small amount of money without realizing that doing so sets the stage for expensive repairs down the road.

Cleaning The Fuel Injectors

A lot of mechanics suggest cleaning your fuel injectors every 30,000 miles to ensure they remain unclogged and able to deliver an efficient spray pattern. If you have never taken the time to clean them, you will likely notice a marked improvement in your engine’s performance.

To start, if you lack experience working with cars, you should leave the cleaning to your mechanic. The job takes less than half an hour, but can seem complex, even when cleaning the FIs while they’re in place. You’ll need to use special equipment to feed the cleaning agent to the fuel rail (while your engine is running). You’ll also need to disengage your fuel pump and block the return line. As a side note, taking the fuel pump offline may cause a fault code; it will need to be cleared after you’ve finished cleaning the FIs.

Once the cleaning agent has gone through the engine and your fuel injectors, engage the fuel pump (clear the fault code, if necessary). You should be able to examine the injectors to determine whether all obstructions have been cleared. If a blockage persists, you may need remove the FIs in order to perform a more thorough cleaning.

Dirty fuel injectors are a common problem, especially in cases where drivers use low-priced gasoline. Plan to have the FIs cleaned every three or four years to ensure they remain free from clogs.


Source by Everette R. Jamison