When does an engine run at idle speed?
Idle speed (or idle) is the rotational speed an engine runs at when the engine is idling, that is when the engine is uncoupled from the drivetrain and the throttle pedal is not depressed. In combustion engines, idle speed is generally measured in revolutions per minute (rpm) of the crankshaft.
Why does an air conditioner raise the idle speed?
Most air conditioning-equipped engines have an automatic adjustment feature in the carburetor or fuel injection system that raises the idle when the air conditioning is running. Engines modified for power at high engine speeds, such as auto racing engines, tend to have very rough (uneven) idle unless the idle speed is raised significantly.
What should I know about BMW E30 idle speed?
This article is intended for you to learn a little something about your car, and at the same time, point you in the right direction towards fixing that erratic idle. Keep in mind that this article is specific to the 1987 through 1991 E30 6 cylinder cars, however the basics apply to nearly all BMW’s.
How does the idle control valve work on a BMW?
The idle control valve controls the amount of air that bypasses the throttle butterfly and keeps the engine idling. The throttle switch is used to control the idle control valve. Essentially, when the throttle is fully closed, the throttle switch sends a voltage to the idle control valve.
What does idle mean on a car engine?
Engine idle refers to keeping the engine running when the vehicle is not in motion. Generally, idle speed is just enough to keep the engine running without stalling out.
Why does the idle go up after cleaning the throttle body?
The idle is going to be high at first until the computer relearns the idle again. Cleaning the throttle body allowed more air to enter the engine, and the computer is compensating by adding more fuel.
What causes the idle speed to be high or low?
What Causes Engine Idle Speed to be High or Low On a modern fuel injected engine, engine idle is controlled by the engine control unit (ECU) and an electrically operated throttle control module. When the idle is high or low, it could be caused by a malfunction of this system or any of the individual components that comprise the system.
What’s the high idle after a carb cleaner?
High idle after throttle body cleaning throttles engine i… I cleaned my throttle body with carb cleaner about 5000 miles ago. My car used to idle at 800 rpm, but now, when the engine is cold, it idles at about 1500 rpm, going down to 800 as the engine warms up.