I have a 2001 Accord V6 with 189XXX miles. For about the past 8-10 months, it will start normally at first, but after being driven for a while or started within an hour of being but off, the rpms go down to about 300-500 and then after a second something kicks in and it idles normally. This happens more often when it is hot outside and sometimes it will 'search' for rpms when idling (after I have been driving for a while and its fairly warm outside) and the RPM drops and then will get back to a normal level after a few seconds. This is more common when the air conditioning is on but it is still concerning. I love this car and hope it is nothing major. I trust it to take me anywhere, however, I would like to fix whatever is wrong before it turns into something worse.

 

Clean your IACV.

 

It also could be alternator starting to go, but more likely iacv.