Idle issues with Adaptronic Select
 

I'm using the RX-8 Select ECU, RX-8 front cover, and a REW swap for the rest. A full list of mods done is can be seen here https://www.rx8club.com/rotary-swaps...3b-rew-263139/ if that helps. I know the REW portion might technically make this off topic for this forum but I felt it was more relevant here than the engine swap one since I am still using the Adaptronic Select for series 1 RX-8 and the result of idle tuning would probably be similar since they both use the MAP sensor and I'm using stock ECU sensors as well.

I am trying to solve idle issues where it will fail to maintain idle when warm (stall) as well as stall when returning to idle from open loop. I watched the videos on the idle control as well as diagnosing problems with it but feel I'm a bit over my head and was looking for additional guidance before I start making changes.

I've attached logs taken while stationary and doing rev and release to eliminate the speed sensor as a factor (though I'd think it wouldn't be since I'm using the piggyback version getting this info directly from the factory ECU). I've also attached the map as provided by my tuner for reference.

Full disclosure: I'm cross posting this from the Adaptronic tuning forum after I noticed that their thread traffic is rather slow. I am moving it here in light of that. My intention is not to spam this across multiple places.

shouldn't speed1 have fixed this issue? look into shelldude's thread on adaptronic. Maybe something is in there on the issue. I only browsed through it about 6 months ago so i can't remember exactly

I did read Shell's entire thread which is a wealth of information but I didn't find anything specific to idle besides a mention of the adaptive closed loop tune. The car was idling mostly fine when I got it back from the shop after Dave fixed hot IAT stalling at idle issue. Since I got it back however it's now exhibiting an inability to hold idle once warmed up. He thinks that the car is getting too much air at idle and I should start tweaking the VEs. I'd like to get a second opinion before I start doing that. Also, Speed1 is three and a half hours away from me and the car has been there for a long time. At this point I'm unwilling to take it back baring catastrophic failure. I just want my car to idle without dying and learning how to be self sufficient is never a bad thing :)

This shouldn't be too hard to tune out... Dave is partially correct too. Check your AFRs as it starts to fluctuate.... The little WARI dashboard can be very useful here.

Note the Water Temperature and AFRs. There's is a fuel correction table for idle with the primary axis being WAT. If your AFRs are lean you need to increase the correction. If they are rich you need decrease it.

Assuming this is the only problem you should be able to establish a nice steady idle after a session or two of monitoring it reaching operating temp and adjusting the correction appropriately.

Youll might need a idle control valve

Did you get the issue resolved?

Sort of... I haven't had as much time to mess with it as I would like and I just replaced the laptop battery that was only letting me get about 20 mins of tuning done at a time.

I've been tweaking the idle WAT compensation at the 95c+ range where it seems to have its issues. It seems like the trims from 100-105+ WAT are what cause the problems but when I manipulate them a large amount either up or down it will still fail to return to idle while moving. When the car is below 95 WAT it idles and returns to idle flawlessly even while moving. Up until 90 all trims are at 0, so what I'm not fully understanding is why these trims are needed at all?

As an example, today I started the car up, warmed up flawlessly, drove to the store also was settling into idle flawlessly the entire time. Was in the store for ~15 mins and started up and came back home without a hitch, not even hunting. I didn't have my laptop hooked up so I couldn't check the WAT unfortunately. When I had started it up before going to the store there was a new code (which also caused it throw 4 other codes I had previously masked???). After I got back home I turned off the car for about another 10 minutes, re-flashed and reset the ECU but now it was exhibiting the same stall while moving and returning to idle it did the last few sessions. If you manually keep throttle while coming to a stop then let it idle it hunted a little but stayed steady. This also doesn't make sense to me since it seemed like the act if resetting the ECU affected the drivability.

I dropped my 105-110 WAT trim down from 60ish back to the 35 for the 100-105 range and the stalling while moving went away. The car will hold idle when 105+ but still has a tendency to "hunt" even if it doesn't stall. Drop down to ~500 RPM, jump up above 1000, then wobble until it finally finds its sweet spot.

I can throw up more logs if it will help but as it is now I will start tweaking little by little. I must say that the adaptronic log viewer is very nice and makes troubleshooting much easier. If only I could figure out what to do :)

I can also post the when I got it back vs now WAT curve if that helps. One thing that kind of worried me is the correction tab shows "idle as open loop". Does that mean that my car is actually using open loop to idle? Another strange thing is my AEM UEGO wideband shows very different readings than what adaptronic shows. When I'm idling adaptronic says I'm low 14s while my wideband shows high 11s - low 12s. I know it was running pig rich with the previous turbo setup so if the O2 sensor could be hosed.

Closed loop idle may help but only if your AFR input is good (ideally a good wideband sensor like an Innovate one). Your wideband sensor should be wired into your Adaptronic and be reporting. You'll know that's the case because you'll see it in the WARI sensors window. The AFR field shows the reported AFR, reference AFR, and target AFR.

I'll be really disapointed if you are not already running with a wideband. Everything is Open Loop otherwise. It sounds like your Adaptronic may be using a narrow band input which would explain the low 14 while your external sensor is reporting 11s. Tune to your external sensor value until you're in the 14.1 to 14.7 range. But keep in mind you will benefit from none of the closed loop features of this ECU.

What is the timing like in that area?

To be clear I can just purchase this wideband sensor have a shop weld it in the downpipe, then plug the cable directly into the unit?

Can I just get this sensor:
Innovate Motorsports Wideband O2 Sensor | Full Function Engineering

Or do I have to spring for the entire combo:
Digital MTX-L Air/Fuel Ratio Gauge Kit (All-in-one) w/O2 Sensor

Edit: I was unable to find a WARI sensors section. I didn't see anything related to innovate in the ports, ecu data, or live gauges however. I think you are probably right and it's using the stock narrow band in open loop since my UEGO was fairly accurate on my previous setup, matching stock when it was in closed loop / stochiometric. I asked Dave about this when I picked the car up and he said it can't idle there since the ports are too big...

You mean the timing in the idle or in the fall back to idle area?

Both ;)

I believe you would want the LC-1 if memory serves correctly. The LC-1 would connect to your Adaptronic via it's secondary serial port (exposed via a 1.5mm stereo plug).

There are other ways to wire in your wideband. You could likely wire in your existing sensor if it has outputs (most do). You would need to pop the cover on your Adaptronic and wire it in via the external inputs if memory serves correctly.

MTX-L w/serial cable is what you want.
Im using it.... just plugs right in to the ECU.
Bought mine from turbosource and had it in my hand in 3 days.

Innovate Motorsports MTX-L Wideband Air/Fuel Ratio Gauge

Another update. The idle problems have entirely sorted themselves out with the change I made in the last post and potentially the temps dying down. There is subtle hunting sometimes on return to idle and it idles rich still. Those issues aside it returns to idle and holds it like a champ now with no additional stalling events. I am going to wait on the innovate O2 sensor / closed loop project until early next year to get prepared for Deals Gap Rotary Rally and drive until winter in its current state. I am eager to improve on light throttle, cruising, and idle after I have the narrow-band but I have to give the project a break until then.

Thanks for all the help :)

keep in mind that you are going to be seeing an ever changing tune open loop due to any number of environmental factors.

You can run fine one day and rich / lean the next.

Another update. I was forced to reset my ECU today after somehow my CEL-free 250 miles ended in emissions test fail as just plugging in the diagnostics caused some U lights to be thrown. The relevant bit of data however is, that flashing/resetting the ECU absolutely is the cause of the idle issues. Immediately after I did it the car was back to being unable to hold idle. So something in the stock ECU relearning causes my idle to go to shit. I will be putting drive cycles on it more aggressively to come and will see at what approximate mileage it goes back to a steady idle.

You have to wait for your LTFT to go to max. It has been some time but I remember fuel trim also being a culprit for out of whack AFRs.

I now have an Innovate LM1 hooked into the adaptronic but I'm still having some issues with the idle. Essentially I can't seem to get the AFR above 13.1 or so without it dying. I've been playing with the target AFRs, closed loop proportional and integral gains are set to 1, and the correction percentage can't seem to exceed 19% without it causing problems. I watched the Adaptronic videos on closed loop but they sort of gloss over the correct procedure for tuning the idle.

Is trying to get stoichiometric as a goal unreasonable? There is a period where you turn on the car where the LM1 is not showing the AFR, is there any way to eliminate or reduce that time? Could anyone give any tips on the correct way to hone in on a perfect idle?

Perfect idle is what the engine wants to idle at 😎

Mine's a 1/2 Bridge and it won't idle below 13.1....

There's really no secret...just play around until it idles well...and don't worry about the AFR guage.

Even a street port REW won't like to idle at Stoich....

You could try the Renesis trick of idling on the T plugs if the ECU will let you. Mazda did it to get the idle AFR's leaner