Notices
MEGAsquirt A place to collectively sort out this megasquirt gizmo

IAC Inflection point?

Old May 8, 2011 | 05:32 PM
  #1  
kjoudrey's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: Jan 2009
Posts: 67
Total Cats: -1
From: Boston
Default IAC Inflection point?

Has anyone ever experienced an inflection point in their IAC valve? That is, when using the idle valve test, in the lower % (say around 10) idle seems low, stays approximately in the 950 range until I get to 30%, then it lowers even more, in the 850 range, then as I increase the % the rpms increas as well.

Anyone ever experienced this? The reason I ask is because when in CL Idle mode, if the steps drop all the way down, my rpms are still high (1200ish) and the controller thinks it has no where to go since the steps are already low (20 steps, 7.8%).

The stock computer handles everything fine, which leads me to believe I have a setting wrong in my .msq. I attached my msq for reference.

The rpms at 20 steps still seem higher than the should be, which is probably what I am really trying to figure out.

Please let me know if you have any ideas. Thanks!
Attached Files
Old May 8, 2011 | 05:40 PM
  #2  
Reverant's Avatar
Elite Member
iTrader: (10)
 
Joined: Jun 2006
Posts: 6,020
Total Cats: 369
From: Athens, Greece
Default

The lowest you should go is 30%, below that the RPMs will actually start rising.
Old May 8, 2011 | 05:55 PM
  #3  
kjoudrey's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: Jan 2009
Posts: 67
Total Cats: -1
From: Boston
Default

That is exactly what I noticed. Phew. How do I prevent the MS from going so low? I set my Idle Valve Closed Duty to 30, and Open Duty to 65, but the MS will still allow the % duty and steps to go below the 30.
Old May 8, 2011 | 06:05 PM
  #4  
Reverant's Avatar
Elite Member
iTrader: (10)
 
Joined: Jun 2006
Posts: 6,020
Total Cats: 369
From: Athens, Greece
Default

If MS2, "Min duty for PID".
Old May 8, 2011 | 06:14 PM
  #5  
kjoudrey's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: Jan 2009
Posts: 67
Total Cats: -1
From: Boston
Default

Holy crap I'm dumb. I should have known that. Thanks for the dope slap. I need that once in a while.
Old May 8, 2011 | 06:40 PM
  #6  
Greg G's Avatar
Junior Member
 
Joined: Jun 2007
Posts: 411
Total Cats: 0
Default

I do notice some 'looseness' to that. I have Both idle closed duty and min duty for PID set to 30.1, but I sometimes see duty drop to 29.5. Not too big an issue, but it does leave me scratching my head sometimes trying to figure out why it does that...
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
Apr 12, 2021 04:21 PM
chris101
Miata parts for sale/trade
2
Oct 9, 2015 09:08 AM
shooterschmidty
Engine Performance
8
Sep 30, 2015 10:28 PM


Thread Tools
Search this Thread

All times are GMT -4. The time now is 06:53 AM.