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Idle troubles

Old 05-08-2019, 07:40 PM
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Default Idle troubles

So this past weekend I upgraded to sequential injection on my NA6.
Before this I had very few issues with my idle other than it liked it a little rich. Switched to sequential and suddenly /everything/ was absurdly rich.
Changing my VE table was no problem but I can't seem to get my idle correct or repeatable now.

Basically my issues are as follows: Idles lean on hot start and very slowly richens back out. MAT/heatsoak ruled out because MAT correction set to 100%
Oscillation. It oscillates about 50-70 rpm but it's audible and I can see the idle PWM and advance correcting it. Cold starts are slightly rich and also have the same oscillation but are more stable.

What I've tried, all to no avail: changing idle timing. Was at 20 degrees with batch fire, tried everything between 10 and 20 degrees at the suggestion of some old threads quoting 10-15 is proper.
Changing idle VE (obviously) to target 14.3 when hot.
Increasing WUE to timed as opposed to rotations
Ignore MAT corrections on -> off
Turned idle tuning mode from advanced to basic (no change, dont even remember having advanced on)
Idle advance timing correction from engine state to PID

Note: My wideband is currently wired to a switched 12v and goes through heat cycle when the key goes to "on" and after cranking, but my woes persist through that time.
I'm not really looking to have my hand held here, but I've tried too many things to not ask for a push in the right direction.
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WigglingWaffles is offline  
Old 05-08-2019, 10:25 PM
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Looking at your tune I see a few things that might help.
  • Under your closed loop idle settings you have your idle valve minimum duty set to 34%. Was this an accident and did you intend to set it to 24%? I also have an na6 and a number somewhere around 24 was my minimum number.
  • I would also try some more aggressive numbers in your idle rpm correction curve. For reference I think for 100 rpm under target I increase timing by 5 and 100 rpm over target I have it retard timing by 5. I have had good luck with that and some even more aggressive numbers.
  • Your idle ve table doesn't match that close to your ve table. Your idle ve shows significantly lower numbers which would run leaner. Dunno if your idle ve or your fuel ve table is off.
  • If you have hot restart issues your could try upping your ASE taper at those temperatures to give it more fuel as in length of time or in cycles and you can also increase the after start enrichment itself.

Hope some of my input is helpful for you.
andym is offline  
Old 05-08-2019, 10:39 PM
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How rich are you on cold starts? Should be 12.5-13.0.

Hot restart issues come from untuned ASE taper and percentages.
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