You CAN"T, It is NOT ADJUSTABLE it is computer controlled. You have OTHER problems if it is idling to low. Check timing, You need to have the engine scaned with an engine scanner to see if something is wrong with the emminisson system/computer system.
change the bulbs and fuses
it has a low idle. Can also be a vacuum hose leak.
Pull back on the turn signal stalk
One reason a 1993 Chevy Lumina may turn over but not start could be the battery. It may also be the spark plugs.
to turn on the high idle you must run a wire to the ecm /www.kennedydiesel.com:.webloc if you go to this link it will give you the instructions to do it. I did it on my truck and it works great !!! if you have a car starter with an available output you can connect it through that and run you high idle from that.
Not adjustable. Sounds like the throttle position sensor.
Need to know what year, engine size and if it has a carburetor or throttle body injection (TBI).
how to turn the idle down. See if it's carburetor or efi. There is a speed adjustment for either using the idle speed screw (carb) or air bypass adjustment screw. If either has no effect, see below-
Could be you need a new fuel idle motor. Or you need new spark plugs
No. If your idle seems too high turn your truck off, and disconnect the battery cables, wait about 10 seconds, then reconnect. This will drain the remaining "Ground" from circulating. I recommend this process because the idle is automatically set.
Theres a screw on the Throttle body at the end of the intake manifold. turn it with a screw driver left or right.
adjust the idle screw on the drivers side of the throttle body turn it to the right to lower you idle turn to the left to raise it