I went for a short ride yesterday, less than 100 miles. I noticed after she was warmed up idling was below normal and inconsistent.
First suspect would be the gasoline. Poor quality, bottom of the tank, old stratified, etc.
Start the fix with a good dose of an additive and continue this regimen.
I would suggest, to not start to making adjustments while it is in this unsteady state. You may only make things worse.
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