Ask your old gear-head uncle about fuel delivery systems and he will inevitably speak of the carburetor. For most of the existence of the internal combustion engine the carburetor has been the device that supplied fuel to the engine. On many other machines, such as lawnmowers and chainsaws, it still is. But as the automobile evolved, the carburetor got more and more complicated trying to handle all of the operating requirements. 

In order to meet stricter federal emissions requirements, catalytic converters were introduced into the exhaust systems of vehicles. Very careful control of the air-to-fuel ratio was required for the catalytic converter to be effective. The old fashioned carburetors, operated by mechanical components, just could not meet the demand of the new technologies. It was not feasible to achieve this kind of control with carburetors. There was a brief period of electrically controlled carburetors before fuel injection systems took over, but these electrical carbs were even more complicated than the purely mechanical ones. 

Gradually, as new engines were designed, throttle body fuel injection was replaced by multi-port fuel injection (also known as port, multi-point or sequential fuel injection). These systems have a fuel injector for each cylinder, usually located so that they spray right at the intake valve. These systems provide more accurate fuel metering and quicker response.

Removing and cleaning a vehicles carburetor used to be a common repair. Not so much anymore.  Fuel injectors can and do become clogged. Your vehicle will run rough when the fuel injectors are clogged or dirty. Replacement of a clogged fuel injector is not a cheap repair. The cost of the injector can run anywhere from $75 up to $350 each or more. Remember, there is one injector for each cylinder. You can spend as much as $2800 on injectors alone, before any labor charges are even talked about! It’s a good idea to do what ever you can to avoid replacing the injectors when that kind of money at stake.  

Fuel injector cleaners purchased over the shelve at the parts stores are little more than octane boosters with detergents. Don’t waste your money.  A good fuel injection cleaning requires the assistance of a professional. Well equipped shops have “Motor Vacs” which do a real good job of cleaning injectors and other engine emission components. Most shops carry a three part fuel injector cleaning chemical kit. The kit is a less expensive service than a Motor Vac, can be completed in about 45 minutes and does an effective job in keeping injectors clean. The fuel injector cleaning should be recommend as part of your vehicle’s preventative maintenance schedule at least every 30 thousand miles. A little investment in maintenance can save you thousands down the road.