A dirty throttle body might be the problem. Or check the IAC (Idle air control). More than likely its a dirty throttle body which is not that big of a deal to get it clean. Hopefully its not the IAC. That will run you a couple of hundred dollars.
High Idle.
low idle when cold but it goes normal in few minutes
I will talk about fuel injected engines since they have been common on most cars since 1987. Idling problems could be several problems. A dirty idle air control motor , dirty mass airflow sensor or dirty air filter will cause idle problems. Spark plugs that are wore out will cause a cylinder to now fire correctly. A wore or sticking injector will cause idle problems. The most common problem I find as a mechanic for idle problems is a faulty coolant temp sensor. So the three major systems to check are the AIR, FUEL and SPARK .
There isn't one...the idle speed is controlled by the engine management computer and is not adjustable. Idle speed problems are typically caused by a malfunctioning IAC (Idle Air Control valve), dirty throttle plates, or vacuum leaks.
There is a "belly pan' under the intake that commonly blows gaskets causing oil consumption, idle problems, heater shifting to default, etc, etc. Remove the intake and reseal..
The most common cause of a 1996 Ford Escort to idle rough is bad spark plugs or bad spark plug wires. A plugged air filter will also cause it to idle rough.
Two of the most common causes are throttle position sensor and idle control valve problems.
A high idle in your 1996 Pontiac Firebird with a 3.8-liter engine can be caused by several factors. Common issues include a vacuum leak, a malfunctioning idle air control (IAC) valve, or a dirty throttle body. Additionally, problems with the engine's sensors, such as the throttle position sensor (TPS), can also lead to an elevated idle. It's advisable to diagnose these components to pinpoint the exact cause.
A failing throttle position sensor will cause idling problems when the car is warm. The failing sensor can also cause the car to stall when idling.
A 1996 Corsica may fail to idle due to several issues, such as a dirty or faulty idle air control valve, which regulates airflow during idling. Another potential cause could be a vacuum leak, which disrupts the air-fuel mixture. Additionally, problems with the fuel system, such as a clogged fuel filter or failing fuel pump, could also lead to poor idle performance. Lastly, ignition system issues, like worn spark plugs or faulty ignition coils, might contribute to idle problems.
Idle speed control or Idle air control.
Idle is computer controlled and is not adjustable.