Is it bad for your engine to IDL?

Idling for long periods could be disastrously more damaging to your engine then the same amount of time spent cruising.

What’s the difference between high idle and low idle?

Step by step automotive repair guide on how to troubleshoot and fix an engine that is idling high (fast) or low (slow). (Note: The engine idle speed is controlled by the computer and is NOT adjustable.)

Which is more important high rpm or low rpm?

The high rpm range has less torque but more horsepower. An analogy is, horsepower determines the speed which you crash into a wall, but torque determines the speed you have left over after crashing through it. When accelerating on the flat, you can use the horsepower to give faster acceleration.

How much fuel does an idle car use?

Some numbers cited by various no-idle campaigns estimate that 10 minutes of idling uses about 0.1 gallon of fuel (for a small car). If you idle 10 minutes a day, it adds up to more than 35 gallons a year. And it only takes 10-15 seconds worth of fuel to restart the car.

When does an engine go from high rpm to idle speed?

An engine must go from high RPM operation to idle, almost instantly. The idle circuit eases the transition and allows a more controlled reduction of speed. When the idle circuit fails, the engine may stall when we suddenly release the throttle.

How does the IAC system affect the idle speed?

For instance, switching the air conditioning on, increases the engine load. With the IAC system, the computer immediately increases the idle speed to compensate. A cold engine runs with less efficiency and the PCM also commands a higher idle speed. This helps to circulate engine oil and prevents stalling while the engine warms.

How does electronic fuel injection affect idle speed?

When engines had carburetors, they always provided a means of adjusting the idle speed. A simple turn of a screw corrected the problem if the engine’s idle speed was too slow or too fast. With electronic Fuel injection they eliminate the manual adjustment and the computer makes all corrections to the engine’s idle speed.

What happens when idle memory is lost in an engine?

If idle-memory is lost, the PCM may no longer be able to obtain the necessary throttle setting. The engine may stall or idle very low. Correction involves cleaning the throttle and resetting base-idle. Resetting idle may require a scan tool or may occur on its own, after the throttle body is cleaned.