You may have been hearing about the new direct injection engines and want to learn more about them; Some deliver the power of a V8 with the economy of a V6.

For example, in one family of engines the conventional V6 makes about 250 horsepower. The direct injection version of the same engine makes over 300 horsepower and gets essentially the same gas mileage. The turbocharged version makes over 350 horsepower.

So, what are the differences from a conventional engine?

The core difference is in the fuel injection system. The system most vehicles use now is called a port injection system. The fuel injector squirts fuel into a port just outside the cylinder where it’s then drawn into the engine with the air.

With a direct injection system, the injector squirts the fuel directly into the cylinder. The gain in power and economy come because fuel injected directly into the cylinder during the combustion cycle is burned much more efficiently.

First, the fuel is squirted in at hundreds of times more pressure, so it’s atomized much better and burns cleaner and stronger. The other big advance is in electronics. Faster engine management computers can control the additional precision required to manage direct fuel injection.

Fuel injectors are precision instruments. They have to deliver a precise amount of fuel at exactly the right time. The design of the engine also dictates a particular spray pattern for the fuel. If a fuel injector is dirty or gummed up, it can’t do its job as well. That means less power and worse fuel economy and can lead to damaged fuel injectors.

Replacing fuel injectors isn’t cheap. Direct injection injectors, are even more expensive because of the extremely high-pressure they use. Same thing for diesel fuel injectors. We’re talking mortgage payment range to replace a set of diesel injectors.

A professional fuel system cleaning gets out the gum and varnish in the whole system, including the fuel injectors. Keep those injectors clean and they’ll last a long, long time.

All modern vehicles come with fuel injection systems so it’s a topic we all need to know something about. All new cars and trucks in the last 30 years or so have come with fuel injection systems.

The fuel injector is a valve that delivers the gas or diesel fuel to the right place, in the right amount, at the right time; to be mixed with air and burned in the engine.

So how many fuel injectors does a car have? There’s one for each cylinder.  So four, six or eight for most folks.  Some vehicles have 10 or 12 cylinders.  The engine control computer makes adjustments to the fuel injector as it monitors the engine and other sensors.  Fuel injectors are a pretty sophisticated part.

Now most service centers offer a fuel injector cleaning service.  What’s the benefit? In order to work right, the fuel injectors have to deliver the fuel at a precise pressure at a very precise time.  The fuel needs to be sprayed in a particular pattern as determined by the engine design.

Over time, varnish can start to build up in the fuel injectors, effecting the pressure, pattern and timing of the fuel charge.  The result is that the fuel doesn’t get burned as efficiently as it could.  That robs performance and wastes fuel.

What about dirty fuel – how does that affect the fuel injectors? The fuel injectors are the last stop in the fuel system.  It starts at the fuel tank.  Frankly, the best way to keep your fuel injectors working well is to use high quality fuel.  Its real tempting to shop for bargains with fuel prices as high as they are, but major brands have better detergents and additives and deliver consistent quality.

What about a good fuel filter? The fuel filter is the next device in the fuel system.  Its job is to filter out the dirt and rust that collect in the fuel tank.  If it’s clogged up, the dirt will bypass the filter and head upstream to the fuel injectors.
It’s important to replace the fuel filter when your manufacturer recommends it. That’s part of a comprehensive fuel system cleaning.

There are different kinds of fuel injection systems. Port fuel injection systems, the kind most gasoline engines have, operate at 60 pounds per square inch.  The injectors for the new gas direct injection engines we’re starting to see require 10 to 30 times as much pressure.  And some diesel engines for passenger vehicles have injectors that operate at 30,000 pounds or more per square inch. There’s no room for dirt and gum in a precision part like that.

There are a lot of good products out there that can clean fuel injectors.  They’re best used to prevent fouling in the fuel injectors.  Many can’t clean a seriously gummed up injector – that requires a profession deep cleaning.  But putting the cleaner in the fuel tank after you’ve had your center service you fuel system will help keep it clean.  Be sure to read the label for directions.

The last new car sold with a carburetor in North America rolled out of the dealership in 1990.  Since then, all new vehicles have had fuel injectors. In very simple terms, a fuel injector is a valve that squirts fuel into your engine.  Your engine control computer tells the fuel injector how much gas to deliver as well as the precise time it should be delivered.  Of course this happens thousands of times a minute.  Fuel injection is a much more precise way of delivering fuel than carburetors. That translates into better fuel economy and power. Virtually all fuel injectors for gas engines are know as port fuel injectors because they deliver the fuel to a port just outside the cylinder.  Port fuel injectors operate at about 40 to 80 pounds per square inch of pressure.

A few auto makers have introduced gas direct injection systems on some engines recently.  These systems inject the gas directly into the cylinders under very high pressure – hundreds of times the pressure of port injection systems.  Although more complicated, direct injection technology promises greater power with improved fuel economy, so we can expect to see more of it in the future.
As you can see, the level of precision required of your fuel injectors is very high.  They need to be operating properly in order for your car to run right.

High temperatures under your hood and variations in gas quality cause fuel injectors to become fouled with wax, dirt, and carbon. Injectors can become partially clogged, preventing them from delivering the proper amount of fuel at the correct pressure. The design of each engine requires a specific spray pattern from the fuel injector that might be altered when the injector is dirty. When injectors are dirty, the fuel doesn’t burn as efficiently resulting in poor fuel economy and loss of power.  So it is important to keep your fuel injectors clean.

Your service center can perform a fuel system service for you.  That is a fuel system service – not just fuel injector cleaning. That is because the fuel has a lot of ways to become dirty or contaminated between the gas tank and the fuel injector. A fuel system service starts with a fuel filter replacement.  This filter cleans the gas as it leaves the tank. The various parts of the fuel intake system need to be cleaned from time to time to remove harmful gum, deposits and varnish. Finally, the fuel injectors are cleaned so that they operate properly and deliver the right amount of fuel at the right time.

Your service center uses a process for cleaning your fuel system that includes state-of-the-art cleaning chemicals as well as some old fashioned scrubbing. Proper maintenance of your fuel system means that you will spend less on gas, enjoy strong performance and prevent costly repairs down the road.