Either the idle screw on the carburettor is improperly adjusted, or you have a vacuum leak.
If you adjust the idle screw as far as possible (usually, a quarter turn or so is plenty) and the idle is still fast, it's probably a vacuum problem.
Check all the vacuum hoses and connections, and around the gaskets for the carb body connection to the engine or the intake manifold. If you can't identify an obvious leak (sometimes you can hear the whistle from a hose with a split), get a carb cleaner aerosol and spray it around suspect areas. If the idle suddenly runs more smoothly (due the fact the aerosol has stopped the oxygen getting into the wrong place), you've found the location of the vacuum leak.
idling too fast - adjust choke
Idle solenoid.
It depends on how long you are idling, or how fast you are going. If you know you are going to be idling for a long time, it's best just to put your car in park.
Car emissions can be reduced by reducing idling time and by driving at a moderate highway speed when possible. Driving too fast and idling are both wasteful in terms of fuel, and increase the vehicle's emissions.
You can adjust the idle air control valve on a 1992 1500 truck while it is just idling. This is done if the truck is idling too fast or too slow. It will help the truck run better.
There are many reasons why your car might vibrate while it is idling. It could be running too hard for example.
Idling too high?
one of the main reasons an engine runs on or diesels can be related to the fact that it is idling too fast. Set the idling down and see if this imporoves
There can be many reasons why a car surges while idling. Some of these reasons are the computer could be dying, or the fuel injector are giving the engine too much gas.
it means the motore is rotating faster a dead stop than it should be.
I sat in my car in the driveway with the car idling, waiting for the kids to come out.
the clutch