I have the following issue and hope someone has insight into how to correct:

At cold start car idles at approximately 1500 rpms, slowly raising to 2500 rpms, after a few minutes it will start surging from 1100 to 2500 rpms, After few more minutes will often start surge from 1200-1400 (or continue to surge 1000-2100). Then randomly change back to surging from 1100 to 2100.

If you disconnect the IACV plug when surging from 1100 to 2400, it drop back to surging from 1000-2100. When surging from 1200-1400, no change is noted in RPMs (or therwise) when connecting/disconnect the IACV. Surging continue when driving under 1500 or so rpm.

Mechanic said radiator was bled several times, i found no vacuum leaks. Also recently had a EVAP Emission Control System Leak Detected code. Would anyone have any thought how to proceed.

Thanks in advance

 

Four or six cyl engine?

EDIT: Read ALL of the title . I'd pull the IAC and clean it as a start.

 

it would be a 4 cyc vteck engine

 

When my wife's 00 Accord started doing that, I ended up replacing the IAC valve (Idle Air Control), and that corrected the problem. On her car it was happening during the summer, and having the AC on would cause it to go away, but as soon as you turned the AC off it would that start cycling the idle.