2019 Silvrado IDLE

[Silspark]

Hi

new 2019 Silverado has single turbo upgrade only, the issue is in IDLE not stable and going into Negative timing
I have adjust many table in torque management but no luck
also I'm seeing Throttle are fighting with torque management


E90 ECU
Silverado 1500 Turbo upgrade
3 bar map sensor

[Ben Charles]

Decrease Virtual Tq...

[Silspark]

I have reduced it in 500 RPM but no luck

[Ben Charles]

It’s not something RPam decreases... it’s actual measurement of TQ

[SultanHassanMasTuning]

i dont have a stock file, but your VVT was very oddupload mas.hpt

[Silspark]

I have modify MassTuning file and getting better

still the are little RPM fluctuating without AC but with AC is perfect

also I have attached the stock file

[MORLOK]

Things to check.
-Keep Virtual Torque stock, should only need to change that with a cam upgrade.
-Dial in MAF
-Dial in VVE
-You might also need to adjust the External Load Table. Log Zero pedal torque and copy that into the table.

One wildcard to look out for. Under Vehicle Connections and Special Functions there is a "Clean Throttle" button. Clicking that made a major improvement in my idle. The engine was always keeping the throttle open too far, letting in too much air, and then pulling timing to control torque. I think the clean throttle resets some learned minimum open setting or something.

Couple overall thoughts.
-I think spark and throttle hunting during idle is cause by the MAF and VVE not agreeing. Small changes to my MAF curve made big idle improvements. Depending on the MAF location on your new setup, there may be some turbulence that will always cause some idle bouncing.
-Negative timing during idle is from the computer thinking it is making too much torque. Throttle clean fixed this for me, also keeping virtual torque stock helps.

Disclaimer: I have not tuned a 2019 and learned most all of this from my 2014 turbo setup. I was not able to open the tune file since I don't have my interface handy.

[Silspark]

there no VVE in 2019+ so I was paying around Virtual Torque tables

there are no Clean Throttle Process in the VCM

I usually doing that in 2018 and below but in 2019+ not exiting

regards

[Silspark]

any ideas

[MORLOK]

Most of the stuff in my last post you probably already knew, and are way ahead of me on this, but I am still intrigued by the puzzle and have some more thoughts.
I pulled up your tune, and looked at the logs.

- On your latest log the spark was better, but the MAF and VE airflow were quite a bit different (VE low). I think this is the root of the issue. Problem is you can't tune VE, and can't force dynamic mode. Have you tried failing the MAF to see what it does? Could it force the computer to learn the new VE? Or you could try to adjust the MAF curve so it generally matches VE at idle and let the fuel trims adjust back and see what happened. The trims could get pretty wild, like +20% or more, but at least the VE and MAF would agree and maybe it would stabilize the spark. I still think using stock VTT and stock External Load is best.

Other thoughts:
- Looks like you lowered the VTT in the idle regions. The idea being that the computer will think it is making less torque and raise spark to make more torque. But what I think actually happens is it opens the throttle more, then uses the spark to try and dial it in, which it can't do and results in spark hunting again. I truly think the only time you should change VTT is when you do something that changes the relationship of torque produced to cylinder airmass, which only happens if you change compression ratio or with a larger cam at idle. Plus your logs show around -50 lb-ft at idle, which cant be true.
- Looks like you also increased external load. The idea being that the computer will think it needs to make 500 lb-ft, and raise spark to do it, but like VTT adjustments, I don't think this is a good option. But then again, you don't have many options..