1988 Toyota Supra engine idle

Engine Performance problem
1988 Toyota Supra 6 cyl Two Wheel Drive Automatic

engine idle at 1000 rpm up to 2000 down to 1000 back up to 2000 unstable I changed the oil washed the motor have not been able to correct the idle impossible to drive have drided everything out it has been a month have blown with compress air every hose going in to throttle body no blockage I think

1988 Toyota Supra

Updated this is for Bob & Ken you said to remove the idle air control valve in my repair manual it is called a idle speed control valve (isc)
i hope this is the same thing I did remove it from the vehicle and cleaned it I also tested the throttle position sensor and airflow meter which are in repair manual specs what next