97 SL Standard, SOHC - Idle Racing

Could anyone suggest what to check for this problem. The engine will idle
at about 1700 and then slowly drop down to about 900. If accelerating it
will climb an extra 200 rpm before slowly dropping back down to normal idle.

I have tried swapping throttle bodies and the MAP with out any change. I
don't have access to a code reader so any comments would be appreciated.

 

Common problems with Saturn engines is the coolant temperature sensor.

If they fail making the computer think the engine is cold, it will idle the
engine at a higher temperature.

About $15 for the sensor, about $20 for the connector to the sensor. The
sensors often leak when they fail, corroding the connector also.

 

What you describe is perfectly normal for a 2002. It won't go to low
idle speed until you are completely stopped. The idle bypass seems to be
programmed to go pretty much full open and stay that way for a few
seconds after you lift your foot. Slightly less annoying after the
engine is fully warm though. I much preferred the 1992 programming which
was similar but much less aggressive about this. Don't know about the 97.
Ken