By now, fuel injector service has become a familiar procedure for most import shops. Nevertheless, many shops have different opinions about how fuel injectors should be serviced. Because many different electronic fuel injector configurations and operating strategies have been used in import vehicles since their popular introduction during the 1980s, fuel injector issues can be more constructively discussed in general terms rather than application-specific terms.

To illustrate, we can generally say that fuel injectors most often fail when underhood temperatures exceed 200° F and when the car is driven at slow speeds or under stop-and go traffic conditions. Because high underhood heat usually increases electrical and clogging failures in fuel injectors, fuel-injected vehicles driven in metro areas may generally need more maintenance than vehicles driven in rural areas.

We can also generally say that many late 1980s and early 1990s fuel injectors fail more often because of poor design, inferior materials or historically prolonged exposure to poor-quality gasoline. Some fuel injectors of that era tended, for example, to clog quite frequently while others made with faulty materials could develop dangerous external fuel leaks. When such failure patterns are present, replacing fuel injectors in sets is highly recommended.

In addition, many discount gasolines simply fail to keep an injector nozzle clean under adverse driving ...