Time for a tune-up?
What is a tune-up?
In today's world of electronic ignition and computer controlled fuel delivery systems, the idea of a tune-up may seem outdated. In the past, a tune-up included changing spark plugs and filters, as well as making basic engine adjustments such as timing, idle mixture, and idle speed. However, spark plugs last longer than ever before and recent advancements in engine management systems have made most of these basic adjustments unnecessary. So are tune-ups a thing of the past?
The tune-up may not be a thing of the past, but its definition has certainly changed. With the introduction of computer controls, there is a greater need for optimum performance by all the components in the system, including associated sensors, actuators, and other engine components. If even one sensor is out of calibration, it can upset the entire balance of emissions and fuel economy. An engine component failure such as a burned valve can cause major changes in engine operation. The excessive hydrocarbons can overheat the catalytic converter and the extra oxygen will drive the feedback system rich. That is why all parts must work together to achieve peak performance.
Performance is the operative word when discussing a modem tune-up. When a customer brings his or her car in and asks for a tune-up, they are really saying, "I want my car to perform better." They do not understand things like closed loop fuel control, electronic spark timing, or idle air control systems, but they do know when their car is not behaving the same as it used to. Symptoms such as cold start problems, surging, poor fuel mileage, and dying at stops are just a few of the items that will cause a customer to come in and ask for a tune-up.
The term "tune-up" is familiar to most people. However, its meaning varies from one person to the next. Technicians generally think of a tune-up as replacing spark plugs and checking timing, idle speed and idle mixture. A customer may not think of a tune-up in the same way. After all, if a customer takes his bicycle in for a tune-up, he knows the bicycle mechanic won't install new spark plugs, but he does expect the bike to perform better when the work is completed. The brakes will be adjusted, the tires aired up, the chain oiled, and so on, all under the guise of a "tune-up."