We have been experiencing extremely hot weather as much of the US.

When I got in my car to drive home from work Friday the Battery/Charging System light was on. I had the battery checked and the parts store said it was "bad". I know I should have done more testing, but the battery was almost 5 years old and they pro-rated a new one. Light still on.

Saturday morning I decided to tackle the alternator. I was able to get a new one installed and the light has stayed out.

Sunday morning on the way to church and the RPM's dip and the car stalls. I restart and it won't hold an idle. I limp back home. In my novice attempts to discover what could be causing the issue I unplug the wiring harness attached to the Throttle Body Motor. The check engine light comes on but the car idles perfectly.

I pulled and cleaned what I believe is the air temp sensor on top the side of the Throttle Body which lead to the harness. It was very black but cleaned up with a clean towel. No change to the idle. I pull the sensor on top of the throttle body but can't see anything but a small round opening so reinstall.

What is a next best step? I know it sounds like I'm all over but I'm stressing about not having my daily driver. Any suggestiong are appreciated!

 

So the sensor on the side (actually mounted in the intake manifold real close to the throttle body) is the air temperature like you thought.
The one on top of the throttle body is the manifold pressure sensor.

When you unplug the harness for the throttle, it idles OK because the throttle motor goes back to a position to allow that.
When the throttle harness is plugged in, does the check-engine light come on? Do you have a scanner to read error codes? Better yet, do you have a scanner that can read live data?

Not sure I can help because I never had a V6, but just asking some basic questions to get the discussion going...

 

Thank you so much for your reply Jim. I do have a code reader and when the harness was plugged in there were no codes, only when I unplugged it. Helpful to know why it did idle when unplugged! I'm learning with each problem solved

A friend sent me this YouTube video on resetting the idle, which when I follow it resolved the idle issue! It is running better than it was prior to all of these issues.


I had followed another idle reset video previously that was not as complete as this one and did not fix the problem. When following this reset and after the 5 minutes at 3k RPM's it did not idle, but, I kept my foot on the accelerator enough to keep it running through the two fan cycles and then the A/C run for 5 minutes. I've owned this car for 10+ years and never knew it needed to re-learn to idle!

Hopefully, this will help others with this issue.

Stay Cool!