Hunting Idle on Cold Start??

[Calcoe]

Hi all, this is my first post so apologies if it’s wrong

HUNTING COLD START

I’ve got a 2020 Seat Leon 1.5 MK3.5

Running into a problem with cold starts, does it on a completely stone cold, cold start as well as 45 minutes to an hour it’ll do it too.

Idle hunts, you can hear it in the video I’ve uploaded, on startup, revs increase to a normal 1000/1200, jumps to 1500, back down to 1000 and you can audibly hear the rpms fluctuate. It’s driving me up the wall and I have no idea what to do. I’ve got no fault codes relating to this (warning sign is my front assist out of calibration).

I had an EVAP Fault Code P04401 (I think?), rectified that by getting a new EVAP line and that sorted it. Could this be related in anyway?

Thank you!

 

[mty12345]

EVAP problem can cause hunting idle if drawing through extra fuel. https://wiki.ross-tech.com/wiki/index.php/16825/P0441/001089

Best way to confirm/troubleshoot would be to look at your live fuel trim data while the problem is happening. If you have large negative fuel trims, then very likely it's fuel from the EVAP system being sucked through when it shouldn't be.

https://duckduckgo.com/?q=P0441+site%3Aforums.ross-tech.com

 

[Calcoe]

EVAP problem can cause hunting idle if drawing through extra fuel. https://wiki.ross-tech.com/wiki/index.php/16825/P0441/001089

Best way to confirm/troubleshoot would be to look at your live fuel trim data while the problem is happening. If you have large negative fuel trims, then very likely it's fuel from the EVAP system being sucked through when it shouldn't be.

https://duckduckgo.com/?q=P0441+site%3Aforums.ross-tech.com

Hi matey, only problem with that is my EVAP issue has been sorted. I no longer have a fault code for it