Stalling after PCM reset

[AdsoYo]

Car has a crate LS3, 216/226-116+3 cam, 0411 PCM using a Lingenfelter box for cam/crank translation, drive by cable, T56. My issue is it will stall when idling and when coasting to a stop after a PCM reset e.g. when I disconnect the battery to wrench on it. Once the PCM learns, it idles and runs great. I just had the battery disconnected to do some work and tomorrow the weather is nice so I plan on driving it but I anticipate this issue happening again. Would you guys mind checking my tune and suggesting possible causes? I'll also post an old log file so you can see what I typically log. Should I be logging anything else for this specific issue? Thanks.

[SiriusC1024]

O2's aren't doing so well at idle. How come idle spark is so high? Should be 18-22* not 35*.

You're running pure MAF. VE table can't be right. If you tune that then return High RPM disable to 4000 idle surge and stall will be more controllable.

[AdsoYo]

O2's aren't doing so well at idle. How come idle spark is so high? Should be 18-22* not 35*.

You're running pure MAF. VE table can't be right. If you tune that then return High RPM disable to 4000 idle surge and stall will be more controllable.

I copy/pasted the high and low octane tables from a 2013 Corvette and then copy/pasted those numbers into the idle spark advance tables to match. Just did some reading and realized my mistake. I will back those numbers down to about 18*.

My VE table is the result of street tuning for a few hours, what seems wrong about it?

[SiriusC1024]

Post a log running SD.

[AdsoYo]

Post a log running SD.

I used the car to do errands today. As expected it would not idle on first start. I had to keep my foot in it until it hit closed loop then it idled fine. It drove and idled fine for the rest of the day. I used the opportunity to tune idle spark and found minimum MAP at ~30 degrees so that's where I set the idle advance table. I'll attach the new tune with my changes, the log from today's first start, and the last time I logged SD which was in May.

[SiriusC1024]

Need a current SD log with the idle spark changes applied. The O2's weren't working correctly at idle before, so if you did SD off that then it won't be right. Not certain that the idle spark is causing it, but it's possible.

[AdsoYo]

Need a current SD log with the idle spark changes applied. The O2's weren't working correctly at idle before, so if you did SD off that then it won't be right. Not certain that the idle spark is causing it, but it's possible.

I don't think it was idle spark causing it because I ran it up to 30* before closed loop kicked in and it still wouldn't idle. Although if you look at spark as it gets close to stalling it swings wildly up and down. Don't know if that's normal. AFR and idle air valve look ok before it stalls. It was hard to start afterwards like it was flooded though. I didn't do any tuning with narrowbands, I use the wideband. I don't see what you mean by the O2's not working correctly in the first log.

[AdsoYo]

To the top. Still open to ideas as to why the car won't idle after a PCM reset.

SiriusC1024 suggested the VE table but I'm running MAF-only. He also said my O2's weren't working correctly in the first log but hasn't elaborated and to me they look fine.

My adaptive idle tables and adaptive idle airflow tables are pulled from a stock 2002 t/a. Base idle airflow, throttle cracker/follower, rolling idle have been adjusted for the LS3. The Airflow > Dynamic tab is pulled from a stock 2002 t/a except for high rpm disable set to 400 rpm. I made a bunch of changes under the fuel tab. I copied LS3 tables for Fuel > General, and made changes in the Oxygen sensors tab to account for long tubes and personal preference. Spark advance tables are all from the LS3 file.

In the log, the saw tooth pattern makes it look like the engine keeps swinging too lean. Then there are those sections right before it stalls where spark goes whacky. Is that the PCM trying to save it? Could it be stalling because of lean fueling?

[SiriusC1024]

Why do I need to elaborate? Do these O2's look fine?
idle o2.png

The fact that it runs fine after learning tells you that fuel trims are the problem. I told you to tune SD so that airflow can be predicted as RPM changes.

Tune the VE table with the narrowbands. Put it back into hybrid dynamic air afterward. Set idle spark right. MAF only is idiotic.

If you've got it all figured out then why ask a question? I'm telling you one more time how to fix it. You're on your own now.

[AdsoYo]

If you've got it all figured out then why ask a question? I'm telling you one more time how to fix it. You're on your own now.

Doesn't take much for you to lose your composure does it? Didn't realize you're so fragile. I love how you say I'm on my own as if you're the only one on this forum who could possibly help. So you're fragile and arrogant, hell of a combo.

I can't believe how instantly hostile you became simply because someone didn't eat up your advice. You've got such a terrible attitude and it takes the fun out of engaging in this forum. This is supposed to be a place where people elaborate because that's the point. Share knowledge, be helpful. You haven't done either of those things.

[SiriusC1024]

I've already helped you a lot:
https://forum.hptuners.com/showthrea...oks-rediculous
https://forum.hptuners.com/showthrea...183#post758183

Then I help again and you want to be a dick about it?

Seriously, you've been messing around with that tune since last May? You haven't even followed the advice of many good tuners in those past threads to end up where you are now. You have fun doing whatever it is you do.

[AdsoYo]

Then I help again and you want to be a dick about it?

Lol your poor little ego.

Seriously, you've been messing around with that tune since last May? You haven't even followed the advice of many good tuners in those past threads to end up where you are now.

Either paying attention is too hard for you or you're doing a horrible job at trolling. Probably the former. You pulled that whole statement out of your ass.

Once the PCM learns, it idles and runs great.

Couldn't have done it without their help. You need to check yourself.

EDIT:

I'm going to respond here to the post underneath so this doesn't go back to the top. There are plenty of fantastic helpful people on this forum and SiriusC1024 isn't one of them. Doesn't matter if he's the top poster, doesn't matter if he helped design the PCM! Douchey behavior like his should not be tolerated. It brings this whole forum down.

[SiriusC1024]

Your IAC is too high. Follow this procedure:
https://www.pcmofnc.com/2021/03/05/i...throttle-body/

That'll help the return to idle stalling.

Your airflow models that were tuned with wideband are inaccurate. That's why it runs poorly until fuel trims can compensate. Still need to retune VE and MAF with the narrowbands then run dynamic air in hybrid mode. Fix your spark.

As you do these things, which there's no way around if you want it to run right, you'll think of me Hopefully you spend another 8 months trying to prove me wrong lol. Enjoy.

Oh one more thing. What does setting O2's as a personal preference even mean? Do you have some sort of opinion on reality? Here's how it's done if you ever become inclined to tune correctly:
https://forum.hptuners.com/showthrea...LTFT-histogram