VE tune question....quick and general
VE tune question....quick and general I have been tuning my car in SD mode, logging for VE tuning. I put the car in SD mode, logged, changed the VE, but did NOT re-flash the PCM with the changes. I then logged twice more and changed the VE table 2 more times. I haven't flashed the PCM since I set it up for SD mode.
Do I need to flash after every change, after every scan? So the PCM sees these changes and then lowers the trim values?
Thanks
Andy
Do I need to flash after every change, after every scan? So the PCM sees these changes and then lowers the trim values?
Thanks
Andy
Yes, you need to flash after every change to the VE. If you log 3 times and never reflash the PCM, you'll overshoot and compound the correction. Think about it for a second. The VE table stored in the car's PCM hasn't changed. But, you've changed the VE table in the tuning software multiple times. So, you're logging the settings of one table and changing a different one each time. That won't work...
Example:
Log 1:
Cell = 40kPa & 2000 RPM
%Error = 3.2% lean
Log 2:
Cell = 40kPa & 2000 RPM
%Error = 2.8% lean
Log 3:
Cell = 40kPa & 2000 RPM
%Error = 3.0% lean
If you changed that cell after the first log, it should be fairly close to accurate. But, you don't update the VE table in the PCM...so it's still off ~3%. You go out and log two more times. Each time you change the value in the VE table, but don't reflash the PCM. That cell is now ~5.9% rich if you decide to flash the PCM now. See what I'm saying???
Example:
Log 1:
Cell = 40kPa & 2000 RPM
%Error = 3.2% lean
Log 2:
Cell = 40kPa & 2000 RPM
%Error = 2.8% lean
Log 3:
Cell = 40kPa & 2000 RPM
%Error = 3.0% lean
If you changed that cell after the first log, it should be fairly close to accurate. But, you don't update the VE table in the PCM...so it's still off ~3%. You go out and log two more times. Each time you change the value in the VE table, but don't reflash the PCM. That cell is now ~5.9% rich if you decide to flash the PCM now. See what I'm saying???
Last edited by SSpdDmon; Aug 10, 2006 at 07:47 AM.
Thats what I thought. I am going to have to start over from the beginning tonight. I will reset the fuel trims again, and go 3-5 scans, flashing each time. I need to organize everything and get the bins/scans together.
I'm kinda bummed since I did all the logging last night, and I am still in SD mode right now. I will post up if I have issues. Otherwise I will get to tuning!
The reason for the VE tune is I inputted the ls6 timing and PE tables since I run an ls6 cam/intake.
Thanks for the reply
Andy
I'm kinda bummed since I did all the logging last night, and I am still in SD mode right now. I will post up if I have issues. Otherwise I will get to tuning!
The reason for the VE tune is I inputted the ls6 timing and PE tables since I run an ls6 cam/intake.
Thanks for the reply
Andy
Originally Posted by joecar
Are you running SD with closed loop...?
Thanks
Andy
Originally Posted by White.Lightning
I do not know. MAF unplugged, MAF fail freq to zero, DFCO to 284*, COT disabled. Please elaborate.
Thanks
Andy
Thanks
Andy
