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

 

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

 

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.