The idle speed is set at the factory and is NOT adjustable.
Timing and idle setting maybe computer controlled and not adjustable. If they are adjustable should be 825-850 RPM
Idle speed is normal.
There is a idle screw on the throttle linkage on the carb that you can turn to increase the idle speed and then hook up your timing light to check the timing.
The idle speed for a 1991 Toyota Land Cruiser with the 4.0 3FE engine should be set at 650+- 50 RPMs. This is adjusted by the screw just above the throttle position sensor on the middle of the intake plenum. I have a 1991 LC and this is where I adjust after the timing is set.
There is a sticker under the hood that tells what to set the timing to and at what idle speed.
try adjusting the ignition timing(or getting a mechanic to do it)
under the hood there should be a white sticker with idle speed and timing on it you cannot set timing and idle on a 2.3. all that is controlled by the pcm
The idle is preset and controlled by the Idle Air Control Motor. You may have a dirty throttle plate that could cause a problem.
This vehicle is probably fuel injected, and there are no provisions for idle adjustment.
1982-1985 ..ht4100 (4.1L) timing 10 degrees BTDC in park idle speed is non-adjustable 1982-1985 .. 307 (5.0L) timing is 20 degrees BTDC@ 1100rpm idle speed is non-adustable