EP3 Any help on idle surging would be greatly appreciated.

So a little backstory I off roaded my car for like 3 months. Had the common idle surge issue jumping between like 1-2k revs. A bit of 8k treatment cleared it after 5 mins.

Offroaded another 6 months and unsurprisingly returned.

This time it’s not clearing. I changed the iacv and it still persists. Do you guys have any clue what the next most likely cause is? Haven’t checked for any leaks yet.

Changed for a new IACV or 2nd hand?

Leaks would be the next likely suspect as you have said. Throttle body and intake manifold gaskets being prime suspects.

Another is that it could just need to re-learn idle. Was the battery flat or disconnected for that time? Unplug the ECU fuse for a 10 mins, plug it back in and try again.

Try fitting one of these...

https://www.tegiwaimports.com/k-tuned-idle-air-assist-delete-kit-honda-k20a-01-06.html

Yeah it was a second hand refurbished oem iacv. Battery was dead majority of the time will check for leaks and get a working throttle body with sensors next. And I was thinking it may just need to relearn idle too. Will unplugging the fuse reset it then? Or do I have to do the whole procedure where you hold like 3k revs until fan comes on and then leave to idle for 5 mins? Just feel like it needs a good drive but the idle issue is stopping it from passing mot. Thanks for replies

Will give it a go mate if no leaks or a working throttle body doesn’t fix it. Cheers