Startup Idle Issues
 

Hi guys, I've been tuning my car for about a year now. For some reason I can't consistently get my car to start. I've tried messing with damn near every parameter I can think that would affect startup and my overall conclusion is that nothing i've tried has had a substantial impact. On my datalog taken seconds apart from each other on the same tune I have conflicting starting problems. In datalog 1 the car starts fine and slowly settles down to target rpm. On datalog 2 the car starts then has a sudden dropoff on IACV % to almost my minimum value range then it shoots back up then tries to drop again then settles back down. I can't figure out what would cause this to happen on 2 back to back attempts.

Attached is my tune and both datalogs.

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I don't have the high $$$ Megalog viewer, thus I cannot open the mlg files.

If you are willing, go into TunerStudio and go to Options / Data Logging Preferences / Data Log Format / ASCII
Then take new logs in .msl format, which I can open.

DNM

Attached are the same logs just converted to the file format you requested.

I guess I just needed to update my MLV? Both kinds of files open now.
What is happening on the bad one, is that you are falling out of CLI. Turn on Status 2 (or look at it in the bottom section) and you can see it. S2 = 132 is CLI engaged.
1st thing I'd try is to change CLI PID Delay from 1 to 3. Even though this should not be involved, being less than 3 does indeed cause seemingly random CLI engagement issues. It is a pain to have to wait every time you stop, but it is more repeatable.

I don't see anything else causing you to go out of CLI.

I tried what you suggested and that seemed to help in addition to some other tuning efforts I made. Stalling right after startup is no longer an issue. I did however come to find out that my pid tuning needs some attention. Everything I thought I knew about pid tuning seems to be not entirely right with respect to my tune. So I will be re researching how to tune pid again.

For reference this is the current state of my tune now.

Woah, that's a crazy amount of D. What are you trying to solve?

To be honest, I am not sure. PID tuning is not my forte. I was changing the values arbitrarily until overall car idle stability felt improved.