Hondata

Guys,
I recently swapped a K24 into a miata.
It has been dyno tuned, runs great. But the idle has me stumped.
I've tried everything... I think - that's why I'm here.

Here's the setup -
K24 with Drag Cartel drop in cams
Skunk intake manifold, 74 mm throttle body (B series with B series TPS)
Remote IACV using this setup: (brand new valve)
https://kmiata.com/collections/intake-s ... mote-block

Required info:
Kpro bought thru Kmiata, SN 46932
Software ver 4.3.5.0

The idle will drop after revving the engine. If the lights / fans / etc are on, it becomes significantly worse and dies.
If I disable the iacv and plug the port, adjust the TB and the dip still occurs. Tps has been adjusted and calibrated.
No vacuum leaks, nothing else terribly obvious. I even went through and replaced all grounds just in case (no change)
My tuner has tried a few things, but no luck.

What light can the Kpro community shed on this? I've spent waaay to many hours trying to figure it out....

The first 3 throttle blips on the datalog are without headlights, the last 3 are with lights on, and the drop is worse. If I turn on the fan, it will die.
Let me know what you'd recommend trying.

I'm not very savvy at Kpro or tuning in general. I've adjusted the IACV duty cycle, and can't get a good balance.

Thanks all!
James

If it is occurring based on electrical load, then it sounds like you have the dead times for your injectors set incorrectly. You should contact the manufacturer of the injectors to get the correct dead times.

Well heck, I think you were right!
Thanks so much for the tip.
I have 410 CC rdx injectors, looked up the values, plugged them in, and all seems good after relearning the idle.

I really appreciate the help Spunkster!

Guys...
Been a while.
Had to take a little time off from the car due to other "stuff".
Finally back at it again.

My tuner has tried everything he knows to try. T

I still can't get a stable idle / slow tip in. It's better thanks to the input above, but still not acceptable - I would assume I shouldn't settle for this? The idle is no longer affected by electrical loads.

Take a look, current kpro file, as well as 2 data logs I just did - one warm and one cold.

I have read everything I can, I have gone over the engine with a fine toothed comb. Cannot find any leaks. Have gone thru the kpro file, but I'm no pro at this stuff. Tried tweaking a few things - but I'm afraid to do much of anything....

I'm in a desperate need of help, but living in this area, don't have much local support.

Any tips???
Thanks!

Your battery voltage is jumping around a lot and you should try to resolve that first and see if that helps with this at all.

Working on it. Let me see what I can track down.

Thanks again.

Ok, found a pretty ugly ground hidden in the rear of the car. Seems to have helped with the voltage instability.
Same problems though, new datalog attached.

I've been reviewing with my tuner a bit.
He is concerned that the ignition timing is not moving at idle, it stays locked.

Anyone else seen this before? Any suggested solutions?

Thanks!

post the calibration the latest datalog was made with

Attached

You should try this ECU in a known working vehicle to see if the issues are vehicle related.

Thank you.
That's going to be a bit tricky, but let me see what I can do.

One more plea for help....

I'm still fighting this car.
I have gone through all grounds and voltage sources. I have the voltage to the ECU stabilized.
I have tried another ECU with the same results.

The ecu was not adjusting the ign timing at idle. When I enable the speed sensor option, the idle immediately got better, and the ecu began to adjust the ignition timing - Yay! I ran a speed input from my dash to the ecu and it reads the speed just fine now.

Go for a little ride, and it starts missing and stumbling severely on throttle tip in. Get back home and it doesn't idle well at all again, hunting up and down. AFR all over the place. Floor it at idle and it will bog down and die. Gently ease into the throttle and it will rev fine.

If you were in my shoes - what would you do from here? New harness? I'm absolutely disgusted with my investment of time and attempts to remedy these issues. Terribly frustrating - it works for a few minutes and then always goes back to running like crap.

Thanks once again for the assistance guys, any ideas are welcomed.

Is it reading all the sensors correctly?

Yes, I believe so.
No codes.