Newbie to tuning -- Help with setting up VE open loop scanning

[thomasjones]

Folks -

I recently received my MPVI2 and have successfully downloaded the stock ECU configuration. I've also got the scanner software running and have captured a few test files. I've been reading about the process for VE tuning and it seems pretty straightforward, as long as the proper parameters are set correctly. I found this thread to be very useful: https://forum.hptuners.com/showthrea...uning-write-up

Post #17 by Rinkrat456 says this:

Check a few things here to make sure you're not chasing your tail...
1. Did you force the PCM into speed density mode by failing or unplugging the MAF?
2. Did you force the PCM into open loop?
3. Is your open loop EQ ratio table commanding stoich? What is stoich for your fuel? Are you commanding 14.681xx or have you accounted for ethanol added fuel?
4. Are your LTFT's disabled and did you reset fuel trims before starting your first attempt at the VE table?
5. Did you disable DFCO?
6. Did you disable Power Enrichment?
7. Are you using the low octane spark table that you'd like to be using?

Here's what I did to attempt to set things up for scanning the STFT settings.

1. My Jeep uses a MAP, not a MAF, so I didn't unplug anything. I did set the engine\airflow\general\sensed MAP = 'enabled' It was disabled in the stock file and not sure why.
2. Originally I tried setting the engine\fuel\oxygen sensors\coolant temp = 376 deg and the engine\fuel\oxygen sensors\ect rear = 376 deg in order to prevent the Jeep from going into closed loop. However, when I did a test run and ran the scanner, the fuel system status #1 never entered the ready state and the STFT and LTFT were not adjusted. So I took those numbers back to stock and then the scanner showed the fuel system ready and STFT and LTFT worked.
3. Stoich is set to 0.0688 for gas (the inverse of 14.7) in engine\fuel\general\FA stoich
4. I did not disable the LTFT, but I did reset the learned settings for the entire ECU
5. I disabled DCFO by setting engine\fuel\cutoff, DCFO\ECT enable = 376 deg
6. I set all of the PRratio values in the engine\fuel\power enrich\ to 0.0
7. I'm not sure how to address this. I see tables and settings in some of the menus for 'gas' and 'alcohol' or 'flex.' But my Jeep does not have a flex fuel badge and I always run 93 pump gas (10% ethanol). I see in some of the tables that gas is set to assume 0% ethanol, which is not what we have around here, but I haven't made any changes to that effect. I don't see an option anywhere to tell the Jeep I'm running gas or flex.

For reference, I've attached the stock config, my current config and a short run of scanned data. You'll see that the STFT is largely in the red. However, the spark retard is all zeros, so there's no knock. The Jeep is running fine, so I suspect I don't have some settings properly configured to get good STFT data.

Any thoughts or suggestions are appreciated.

Regards,
Tom

2008Stock.hpt
2008VEonlyv3.hpt
2008VEonlyv3Run1.hpl

[Wjjeepman34]

Any updates?
Just here to learn right now
And give you a free "bump" incase you havent figured anything out.

[AC3]

Hey Thomasjones,

• What are your mods?
• What are your goals?
• You should describe your vehicle. 2008 Jeep Rubicon 3.8 V6.. right?
  

Based on these answers, I will try and point you in the right direction. Some quick things about tuning VE.

• You disable all the fuel adders, so don't go WOT (wide open throttle). You will be running your engine lean at a high load (bad idea)
• Keep throttle less than 50%
• You need to reset LTFT after each round of tune changes
• No need to tune VE for anything over 4000 RPM. Need wideband for anything higher than that.

I looked over your logfile and everything seems fine. The other thread says to keep trims between -2 and +2. That's not wrong, but standard convention is that +/- 5% is acceptable. Based on the logs, your tune might be a tiny bit lean just off idle, for like half a second when you hit the gas, around 800 RPM and 30 kPa. I would not be worried about it.