When I first start my car in the morning (it usually about 35 degrees outside), she idles at about 11 hundred rpms and doesn't settle down to 8 hundred rps til I've driven her for about 20 min.
Question: Is this normal?


She didn't start doing this til i tightened down one of my spark plugs and cleaned the throttle body with carb cleaner.

 

I'm wondering the same thing...just changed all the plugs, cleaned the throttle body, didn't touch the MAF. Did all this when I rebuilt the starter.

I don't remember the car idling that high before the maintenance was done. Mine does settle down to a steady 800rpms in about 5 min after startup though. Also a 98 GS400.

Thoughts anyone?

 

Assuming neither of you touched the throttle position sensor, I would recommend resetting the ECU by removing the negative terminal and letting the car sit for a few minutes to start off with a clean slate.

The car just needs some time to adjust.

 

Thanks Thomas, I've done the ECU reset, it's been a week now since the higher idling began. Where is the TPS sensor and can it be manually adjusted or bumped on accident? Mine was probably disconnected during the starter rebuild since the intake was pulled.

 

Thanks Thomas, that did the trick.
In fact it's so smooth now, I pull up to the McDonalds drive-thru window just to hear the motor purr

 

It's a possibility that it was not set properly, although you say that it idles at around 800 after warming up a little which sounds about right.

Here's a picture from the non-VVT-i service manual that may be of help. It's not exactly the same as ours, but it's the same general idea.



Glad to hear.

 

1100 rpm when cold is normal. Mine has been like that since the day I bought it brand new.