that screw is adjusting for more or less air bypassing the TB.
You can adjust that screw in non-diagnostic mode. But resetting the ECU is recommended after doing it. Also after adjusting the Idle screw, checking the ignition timing is not a bad idea.

placing the ECU in Diagnostic mode - with a 92-00 you jumper a plug under the dash just behind the glove box.
Resetting the ECU, pull the backup fuse in the under hood fuse box with the car off and key out. Leave the fuse out for a few minutes, plug it back in and start the car. It's best to let it idle for 5 minutes till the car gets warm to let the ECU relearn everything.