High idle on cold start - TephraMod v7
ISCV Demand Startup CTS adder: VIII, table zeroed out, negligible effect as well. The little success I had was playing with the initial position table, but I can't completely eliminate the spike without going too low in the initial step position.
There is definitely some %demand table that raise the ISCV after cranking. Also, there is obviously some decay time parameter that comes into play.
I'm also on this trial and error, trying to determine the effect of tables.
Good work R/Ternie, I'm suscribed for updates from you. I'll update on my side if I find something.
There is definitely some %demand table that raise the ISCV after cranking. Also, there is obviously some decay time parameter that comes into play.
I'm also on this trial and error, trying to determine the effect of tables.
Good work R/Ternie, I'm suscribed for updates from you. I'll update on my side if I find something.
Possible Solution!
After no success in the CTS Subtractor table, I looked at the Idle section of the Tephra map, and saw that my target idles were all around 1398 and below, so that was not the cause. I then looked at the default stepper targets in neutral and driving, and noticed that there is a huge difference between cold temps and 180 degrees. I tried lowering the values for both neutral and moving, and when I tested it, my idle dropped down to 1500 rpm or lower. So, it may have worked, I need others to confirm though.
Here are the before and after screenshots of those tables:
Before
After
Can someone else please try altering these values as well, and see if it helps fix the problem. That would be great.
Thanks!
--mark
After no success in the CTS Subtractor table, I looked at the Idle section of the Tephra map, and saw that my target idles were all around 1398 and below, so that was not the cause. I then looked at the default stepper targets in neutral and driving, and noticed that there is a huge difference between cold temps and 180 degrees. I tried lowering the values for both neutral and moving, and when I tested it, my idle dropped down to 1500 rpm or lower. So, it may have worked, I need others to confirm though.
Here are the before and after screenshots of those tables:
Before
After
Can someone else please try altering these values as well, and see if it helps fix the problem. That would be great.
Thanks!
--mark
Hey i just got my car up and running switched to V7 same Rom ID and started working on cold start issues today, i tried alot of the listed ideas/suggestions up on the other post ect. Just wanted to comfirm that this has worked the best and i have idle almost perfect now, just have some other little bugs to work out now. Good Job!!
I feel some %demand are too strong for certain conditions, but not all of them so I can't play with the lookup table.
Last edited by domyz; Nov 23, 2012 at 11:00 AM.
In my ROM version 8859X715 the tables labeled "Desired ISCV initial step position with XX - XXX" did not show as expected. I believe that this is due to the XML files now distributed in the Tephra v7 XML pack.
If you have this issue you need to do th following:
1. Add mrfred's ISCV control system disassembly code to your XML (https://www.evolutionm.net/forums/7085486-post1.html)
2. Use the updated table names from this post (https://www.evolutionm.net/forums/8872495-post1.html)
For my car I adjusted ISCV Demand CTS Adder #1** to resolve the high idle issue.
Before:
After:
If you have this issue you need to do th following:
1. Add mrfred's ISCV control system disassembly code to your XML (https://www.evolutionm.net/forums/7085486-post1.html)
2. Use the updated table names from this post (https://www.evolutionm.net/forums/8872495-post1.html)
For my car I adjusted ISCV Demand CTS Adder #1** to resolve the high idle issue.
Before:
After:
You don't need to rename the table in the XML.
Keep in mind that XML is like a window for seeing the ROM settings. It contains adresses for data and scaling to make this data readable.
It doesn't contain any data (It can but V7 doesn't)
In other words, you can give a table any name and the ECU won't see that. The only thing that matter is the adress that the table point in the ROM. And only the data (.bin or .rom) is flashed to the ECU.
There is absolutely no reason why a tephra ROM would run differently from a stock ROM.
Send me your old ROM and your new ROM I'm sure of what I'm saying.
IIRC the ISCV stepper lookup tables from the 03-04 ROM (9417) has to be modded to the 9653 one.