E38 - C6 Corvette - Idle issues - TB % will not increase

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December 18th, 2018
SOMFormula

E38 - C6 Corvette - Idle issues - TB % will not increase

I'm tuning a 2008 Corvette 6-Speed
12617631 OS
232/252 120+5 Cam
Stock TB and Intake

I'm tuning Idle in this vehicle. This is the 3rd LS3 I've done this week and I have not experienced this problem before.
Car starts up, revs go up a bit and then the car dies!
I can keep it running by holding my foot on the throttle.

I've done the usual with tables:
B1845 & 1843 (I've even tried zeroing them out)
I've raised up 1651 & 1652 so that I can open up the TB utilizing 1829 Min Airflow

But the TB doesn't want to listen. It seems to always want to stay right at 24% no matter what I do!
So, I then attack the commanded idle in DVT controls and when I command 2k RPM (max), it seems to only idle as high as 1800, if I'm lucky. It seems hit or miss. Sometimes I get a higher idle, sometimes it drops down to only 1200.
I'm commanding 1200 idle just to see if I can get it to stay running. But the most I've seen it idle is 900.
So I'm hoping someone has seen this before and I'm just missing something stupid on this car.

Also, VVE and MAF are within 7% in CL. So I'm good there. I'm seeing a lot of timing, 2x degrees. No negative integers whatsoever. It's bouncing around a bit showing me that the ECU is working on timing.

Thank you for your help!
I hope I got this in the correct section. I didn't know if I should be asking this in the E38 Idle Sticky.
December 19th, 2018
SOMFormula

3 Attachment(s)

Attachment 22576 Attachment 22575 Attachment 22577

I've attached the tune file, stock file, and my most recent datalog
The datalog is from me running SD/CL to try to trouble shoot if I have a vacuum leak (I can't find any with my smoker) or if the MAF was faulty.
I've changed my PID selections around trying to monitor everything I could to get this car to stay running.
Weird thing is, it's been running great for a long time!
Customer went to the dealer to get a recall done and every since its been goofy as hell!!!!
Dealer "flashed" the car back to stock and I then flashed his calibration file back into the car and this has been happening ever since! It just....dies!
December 19th, 2018
Doc

Have you compared the CAL/OS and segments from before and after the dealership incident?
December 19th, 2018
SOMFormula

I did not!
Unfortunately, I didn't "Pull" what the dealership flashed into the ECU.
December 19th, 2018
Doc

I looked at the tune file you posted and compared it to a known stock 08 manual vette that I have in my stock cal files. I did the compare feature and first thing the Operating System, Engine Operation, Engine Operation, Engine Diag, System and Speedometer checksums are different. These different checksums might have been what the dealer "updated?"
December 19th, 2018
SOMFormula

Quote:

Originally Posted by Doc

I looked at the tune file you posted and compared it to a known stock 08 manual vette that I have in my stock cal files. I did the compare feature and first thing the Operating System, Engine Operation, Engine Operation, Engine Diag, System and Speedometer checksums are different. These different checksums might have been what the dealer "updated?"

The stock file was from DropBox.
I never had this cars stock file as it came to me modded.

But good news, I did just drill a 4mm hole in it and I can see that it made a HUGE difference.

I'm thinking the TB was at it's max percentage (24). With the hole in it, it came down to 17% and I can now manage it MUCH better in the tables whereas before it wouldn't listen to me for shit!