Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   Oscillating AFR (https://www.miataturbo.net/megasquirt-18/oscillating-afr-49878/)

pdexta 07-22-2010 04:07 PM

Oscillating AFR
 
I tried to search for this probably but wasn't having any luck. My car is running fine, but when I'm just cruising at any speed my AFR's are constantly bouncing back and forth between 13.0 and 16.5 (the MS reads leaner than my wideband). I originally suspected the MAP signal, but I've moved it around a few times with the same results. Also any changes in MAP (which look minimal to me) do not seem to have a correlation to the AFR. Any idea what it could be?

http://i272.photobucket.com/albums/jj186/pdexta/afr.jpg

18psi 07-22-2010 04:10 PM

smooth out your fuel map?

Jeff_Ciesielski 07-22-2010 04:11 PM

Your closed loop settings are too aggressive. Post your MSQ

pdexta 07-22-2010 04:34 PM

1 Attachment(s)

Originally Posted by 18psi (Post 605464)
smooth out your fuel map?

At cruise it's just sitting in the same cells so there's nothing to smooth, as far as I understand.


Originally Posted by Jeff_Ciesielski (Post 605465)
Your closed loop settings are too aggressive. Post your MSQ

Uploaded. I feel retarded just admitting this, but I have not been able to find anything relating to closed/open loop in TunerStudio aside from idle settings :confused:

ScottFW 07-22-2010 04:46 PM

Your EGO is enabled but the step size is 3% so it's adding or subtracting 3% fuel every time it makes an adjustment. It's possible those swings are too big and causing it to oscillate about the target AFR. Drop the step size to 1%, and also increase "ignition events per step" to something more like 60-80, and see if that makes a difference.

pdexta 07-22-2010 05:31 PM


Originally Posted by ScottFW (Post 605486)
Your EGO is enabled but the step size is 3% so it's adding or subtracting 3% fuel every time it makes an adjustment. It's possible those swings are too big and causing it to oscillate about the target AFR. Drop the step size to 1%, and also increase "ignition events per step" to something more like 60-80, and see if that makes a difference.

Yeah, I'd say that helped a bit. :bowdown::bowdown::bowdown:

http://i272.photobucket.com/albums/j...dexta/afr2.jpg

Thank you!!!!

Jeff_Ciesielski 07-22-2010 06:12 PM

Glad you got it sorted out. Any time idle/cruise are loopy, check EGO/Close Loop settings first. Then look to see if you have some crazy problem with your fuel table or AE


All times are GMT -4. The time now is 01:08 AM.


© 2024 MH Sub I, LLC dba Internet Brands