Go Back  Miata Turbo Forum - Boost cars, acquire cats. > Performance & Tuning > ECUs and Tuning > MEGAsquirt
Reload this Page >

Good times with engine states! Aka wtf is with my idle?

MEGAsquirt A place to collectively sort out this megasquirt gizmo
Sponsored by:
Sponsored by:

Good times with engine states! Aka wtf is with my idle?

 
Old 07-11-2019, 11:00 AM
  #1  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Aug 2016
Location: New Fucking Jersey
Posts: 3,956
Total Cats: 109
Default Good times with engine states! Aka wtf is with my idle?

I've been chasing idle issues for a bit and I'm running into problems with CL idle even kicking on. I've been chasing the issue down and had help from a few folks but I'm stumped. Basically, if I engine brake into idle things are fine ish other than a dip where it threatens to stall... But if I clutch in and coast down from 3-4k then the car will just die without CL idle even triggering.

Then at times in idle itll oscillate on and off and CL idle will just cycle.

Here's a tune and a few labeled logs. Thanks for any help!


https://drive.google.com/drive/folde...xz?usp=sharing
ridethecliche is offline  
Old 07-11-2019, 12:22 PM
  #2  
Design Engineer
iTrader: (1)
 
DNMakinson's Avatar
 
Join Date: Jan 2013
Location: Seneca, SC
Posts: 3,602
Total Cats: 480
Default

Rish,

Some general comments:
1. Set Slow Decel to about -700, else it will drop out of CLI when you don't want it to.
2. Use Initial Values Table. Yes, it is difficult to tune, but pays big benefits. If you use Last Value, you will always have inconsistent results and will chase your tail.
3. On C-L Idle Settings. Set Close Delay to "0". This is just another thing that MS can confuse, and I have never seen any benefit from having the valve close.
4. Have Engine State Settings window open while you drive as it will show you the states and when / if you are dropping in and out.
5. On the oscillation, there are multiple fueling things fighting. I would use an Idle VE Table that has less variation than your regular table in the idle range. Like the big jump from 87 to 91 in the 700 - 1200 RPM range. Also, depending on the exact FW (Released or Beta) the EGO may be a bit fast acting. Anyway, you have VE and EGO fighting to control fueling. I would zero one out and see if that helps. The idle valve is not moving much, so that is not the culprit.
6. You are not using idle RPM Timing Correction. That should be the primary control of Idle.

I am still having a bit of an issue with Overrun MAP needing to be different when using A/C and not. I think if the Use VSS was instead Use RPM, it would fix it. Maybe also the Idle-up CL load Allowance.... a parameter with little documentation, but that, if it worked as I think it should, would fix the issue I have... which is that with the A/C on, I go over the MAP threshold while slowing in gear and then CLI goes on and off. Ugly.

Other than that issue, Idle is working well for me, hence me being willing to make the above recommendations.



DNM
DNMakinson is offline  
Old 07-13-2019, 01:56 AM
  #3  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Aug 2016
Location: New Fucking Jersey
Posts: 3,956
Total Cats: 109
Default

Thanks for those recs! I'll give them a go tomorrow and see how things shake up.

I used to have a VE Idle table, so I'll introduce that back in. Same re: idle valve table. Same for idle RPM timing correction. I think that was funky earlier, but should be able to get it going again. I'll get some more logs going this weekend after spending some time trying to figure things out.
ridethecliche is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
DNMakinson
MEGAsquirt
31
05-17-2019 08:42 AM
freedomgli
MEGAsquirt
10
02-28-2017 08:13 AM
gorillazfan1023
DIY Turbo Discussion
10
11-18-2013 11:54 AM
crnrhrd
General Miata Chat
22
04-11-2010 03:35 AM
rotaryjunky
Insert BS here
10
03-02-2008 03:13 PM


Thread Tools
Search this Thread
Quick Reply: Good times with engine states! Aka wtf is with my idle?


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.