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
For a start remove the idle air control valve and clean it out-Test the throttle position sensor and airflow meter using the repair manual specs then comeback with results this is where we start to find this culprit.
December, 2, 2008 AT 12:37 PM
When was the last time you had it tune-up?
Check the fuel pressure with and w/o the pressure regulator, PCV and EGR valves and vacuum leaks-Test the oxygen sensor and fuel injector/s
December, 2, 2008 AT 12:48 PM
If above checks out could be the idle air control valve itself even if its cleaned out if it continues to surge-