Not adjustable, idle is computer controlled with an IAC stepper motor.
Will vary between 700 and 1000 rpm.
Maybe your air filter or plugs and wires. Or maybe your MAF sensor or your IAC valve needs cleaning.
On the 1992 Cadillac Seville with a 4.9-liter engine, the hose that plugs into the carburetor next to the idle speed control motor is typically the vacuum hose. This hose is part of the vacuum system that helps regulate engine performance and idle speed. It connects the carburetor to various emissions control components, ensuring proper airflow and fuel mixture.
Clean the MAF sensor with CRC MAF cleaner, do not touch the sensor wires, you'll damage the unit and freah is ~ $175.00
Could be in need of a tune up with spark plugs, spark plug wires, air and fuel filters.
On a 1992 Acura Vigor idle is adjusted through a idle control valve. Tightening the valve well raise the lower the idle and loosening it will raise it.
Idle is set by the computer.
have your timing checked it sounds like it out
The high idle may be caused by old spark plugs and wires. As far as the temperature problem there are several things that may cause this, but the thermostat is the easiest and cheapest thing to check.
Check/ replace the TPS if the idle is up and down.
The idle speed is computer controlled and is not adjustable.