Cold start idle surge after certain ECT

[fnee]

I've been having this issue for more than a year after I rebuilt my engine.

Once ECT hits ~45c (based on FP log), idle will surge from ~1.3k to ~2.2k. It only happens when water temperature reads below 50c on my Defi.

I've had two tuners work on my car so far, and another friend who took a look at it. No one has managed to solve the issue so far. I've attached a log from earlier today.

[Spunkster]

What was done when it was rebuilt?

[fnee]

What was done when it was rebuilt?

Ported head, Toda B2 cams, upgraded valve train, higher CR pistons.

[Spunkster]

The idle is very unstable and moving a lot, so it appears there may be some mechanical issue or a leak of some kind.

[fnee]

The idle is very unstable and moving a lot, so it appears there may be some mechanical issue or a leak of some kind.

The cam profiles of Toda B2 is causing this. It also has to idle high otherwise it won't be stable and keeps wanting to dip and stall.

Would sending you my calibration be helpful?

[Spunkster]

You can post it, but it probably will not change anything as it sounds like this is the result of the parts used and the tuning involved.

[fnee]

You can post it, but it probably will not change anything as it sounds like this is the result of the parts used and the tuning involved.

Please see attached.

I'm not chasing the idle issue, but the cold start idle spike when the ECT hits a certain temperature. I don't see how parts used could cause an idle spike at a certain temperature.