E38 L96 Poor Idle Regulation / Stalling

[Alvin]

Sorry late to the party LOL

Your current rev10- file, the idle airflow and rpm tables are drastically different than stock. I compared against 2 different 2011 5.3 OE files.

These PCMs start doing funky stuff when you get too far away from OE settings when it comes to idle, throttle body control, etc. I know you swapped engines but based on the complaints you've had going back to the beginning of the thread, with idle issues, etc., my recommendation would be to put all those settings back to stock and start with the basic changes like increasing base running airflow if needed.

Going back to stock on those settings should cure most of the overshoot, etc.

Actually, I'd start over with your stock tune and change only the engine size and the injector data for the different injectors. Start from there and see what ya got. I bet it will immediately run better.

I agree with this.. Too many times on this forum you see "copy all the stuff out of the X file" That is terrible advice. Get the basics fixed like displacement and start tuning like that engine never came in the vehicle.

There are too many modifiers and what not that we cannot see.

[L96_1500]

OK, so I went all the way back to the as-found tune from the 5.3, changed the displacement, and copied over all the injector parameters from the 6.0 tune. No startup flare but the RPM started oscillating strongly within a few seconds. Log and tune attached.

[edcmat-l1]

Need to let it run longer. It looks pretty lean and the trims never activated. I'd run it another minute or two and see what happens when the trims come online.

[edcmat-l1]

Use this channel config. You have way too many channels going.

[L96_1500]

Take 2, waited longer for the oscillations to die out, then went for a short drive around the neighborhood.

[L96_1500]

Use this channel config. You have way too many channels going.

Did you get a chance to look at the most recent log?

[edcmat-l1]

Narrowbands say it's dead lean the entire time and it never goes into closed loop. I'd recommend you force closed loop using your scanner controls and dial in the VVE and MAF using your short term trims.

[L96_1500]

Narrowbands say it's dead lean the entire time and it never goes into closed loop. I'd recommend you force closed loop using your scanner controls and dial in the VVE and MAF using your short term trims.

Since I am a dummy, I didn't re-disable DoD and Flex Fuel on the last run, which is why it ran so poorly. With that fixed, the drivability issues I'd been having are gone. No startup flare, no wandering idle or stalling, much better drivability overall. Still very lean overall but a huge improvement for daily driving. Thanks for the help.

[MDT]

Was there ever a solution found to this surging idle issue?

[edcmat-l1]

Start your own thread.