As stated there isn't any adjustment! The idle speed computer matches the RPM imput to the engine speed. IF the idle speed stays around 1,100 then have the throttle switch checked out. This switch has a full load & idle contact. IF the switch doesn't close at idle then the speed will remain at 1,000 or higher. THIS is true only for 1981 to 1991 V-8 engines with CIS injection, like your car has.

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