Fuel And Induction System Cleaning

A  service item that's been popping up in repair shops all across the country is the fuel and induction system cleaning service. It involves running a cleaner through the fuel system, throttle body and intake manifold.  

This cleaner removes carbon and deposits from the injectors, throttle and intake, and even works its way down into the combustion chamber and catalytic converter in some cases. 

Many people believe that this is just some type of scam. The fact is that it's a real service with real benefits for fuel economy, engine performance and lower emissions. In fact, it wouldn't be overstating things to call fuel sys­tem cleaning the tune-up for the new millennium.  

Let's start with the why and why not, and then we'll discuss how often you should have your car's fuel system serviced. 

"I never needed my fuel system cleaned before." Not true. In fact, carburetors often were cleaned very thoroughly as part of a regular tune-up. The difference was that the carburetor was wide open, with large passages that the technician could reach from under the hood. 

Most basic tune-ups included cleaning the choke, throttle plate and all of the carburetor passages using a highly caustic, aerosol cleaner. This cleaner removed the carbon and deposits from the entire carburetor and then ran through the engine, where it cleaned away deposits built up on the intake, valves and combustion chamber — much like the fuel system clean­ing service does today. 

What has changed is just how critical this cleaning service has become. That's because today's fuel systems work with clearances and tolerances that measure in microns — some less than half the thickness of a human hair. Even the smallest deposits on these components can have a dramatic effect on engine performance. 

Keep in mind that today's cars must adhere to very strict fuel mileage and emissions standards. Years ago, manufacturers could overcome the effects of fuel system deposits simply by enlarging passageways adding more fuel through the system. 

Today that isn't one of the choices: To meet the standards for fuel economy and emissions, fuel systems measure fuel more precisely than ever before. There's no room for error — or for deposits. 

"OK," you say, "you've convinced me. My car's fuel system needs to be clean. But why does it have to be cleaned by a service technician? Can I just run one of the off-the-shelf cleaners through the gas? For that matter the gas I use claims it includes detergents to keep my car's fuel system clean — why do I need to have it cleaned at all?" 

Let's start with the first question: Do you need to have your car cleaned professionally, or can you use one of the off-the-shelf cleaners? Most off-the-shelf fuel system cleaners aren't effective enough to clean the fuel system properly. In fact, in many cases those cleaners can cause more damage than they correct.                                               

Take a look at the label. Most fuel system cleaners offered to the do-it-yourselfer market use a base of kerosene, alcohol, methanol, acetone or ketones. These are highly flammable, highly caustic cleaners, which cause one of two specific problems:

1. The cleaner's high flammability causes it to burn up long before it can become effective in the combustion chamber. This not only reduces its effectiveness, but also can create additional deposits, compounding the original problem.
2. The caustic nature of these cleaners can damage the fine electronics, seals and coatings in many of today's injection systems.

Fuel and induction system cleaning is a service with real benefits. It can improve performance, reduce fuel consumption and lower emission levels. How often should you have your car's fuel system serviced? Most experts agree that — provided you aren't experiencing a problem — you should have your car's fuel and induction system cleaned yearly to keep it running right.