Car Maintenance: Cleaning Fuel Injection

A fuel injector is an electronically controlled valve which is supplied with
pressurized fuel by the fuel pump in your car. The injector is capable of
opening and closing many times per second. When the injector is
energized, an electromagnet moves a plunger which in turn opens the
valve, allowing the pressurized fuel to eject out through a tiny nozzle into
the combustion chamber of the engine. The nozzle is designed to atomize
the fuel -- to make as fine a mist as possible so that it can burn easily.
Loan
Over the years of use, the small passages in the nozzle can become
obstructed from deposits in the gasoline and external factors found during
normal engine operation. Thus, especially in old cars, fuel injector cleaning
service is needed on all injectors at some point. Most injectors don’t fail,
they just become obstructed. Gasoline is required to have a certain
detergent component that will keep injectors and combustion chambers clean.

So, sometimes cleaning fuel injectors means adding a bottle of fluid to the
gas tank. For removing more build-ups, it needs a mechanical procedure
involving a sort of pressure cleaning and chemical wash costing $50 and up.

However, our advice is, don't do it unless it is directed by the
manufacturer in your manual. Only a handful number of manufacturers
recommend it. If your vehicle is running rough or has become very old, it
might be that there are a number of other causes behind it. Only repeated
injector cleaning may not turn out to be the long-term solution.