By idle speed, what I mean is the engine RPMs increasing and decreasing? Also, have you had a chance to check for engine vacuum leaks?
If not, do that. If there are none and it is the RPMs changing, we should at least try to service the idle air control valve (IAC). Here is a link that explains how it's done:
Before you remove the IAC, please confirm there are no vacuum leaks. To remove the IAC on this requires the removal of the throttle body, draining the coolant, and so on. I don't want you to go through that unless we are confident it's needed.
Here is a pic of the IAC on your vehicle. Again, it's under the throttle body.
Let me know what you find.
Take care and I'll watch for your response.
See pic below.
Tuesday, January 25th, 2022 AT 4:45 PM