High idle on cold start - TephraMod v7
I had major problems with that A/C thing just yesterday actually. I don't want to increase the values in the table for neutral + A/C too much because it causes high idle when standing still. But if its not high enough it dies when the car is just rolling down a hill in neutral, or between low rpm shifts.
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From: spill the blood
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:
Last edited by kruthles; Oct 18, 2011 at 06:37 AM. Reason: Added attachments
Had the high cold 2K idle issue as well with a Tephra V7 2.4L on E-85. Did as the post above described and brought the idle down to 1600-1700 rpms when cold.
Thanks worked great!
Thanks worked great!
Evolving Member
Joined: Sep 2008
Posts: 111
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From: Europe
I may have to rise them a little tough, it's barely at 1500 and I stalled at the first stop (engine cold) don't know if it's related or only because I just flashed it and didn't wait long enough before driving, I'll edit my message when I know why.
If I understand the ISCV right, any iscv-temperature related table may work because all those values are used together to calculate how many steps you will end up with, and the ISCV is managed by way to many parameters really
Last edited by Kakihara; Aug 8, 2012 at 06:52 AM.
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
There is a specific ISCV startup table. Its called "ISCV Demand Startup". Its probably the best table to use to fix this issue.
Last edited by Boosted Tuning; Oct 10, 2012 at 12:12 PM.
Jay I used that table and it really had very little effect on reducing the RPM significantly. I'll mess with it again today to see if I can isolate how effective each is.
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No biss with the boomba throttle body.
I deactivated the SAS via the ecuflash and set the throttle to 900 rpms (target 1000)
RERead:.. thanks Mychailo. I'll set it for 750 instead of 900
I deactivated the SAS via the ecuflash and set the throttle to 900 rpms (target 1000)
RERead:.. thanks Mychailo. I'll set it for 750 instead of 900
Last edited by R/TErnie; Nov 18, 2012 at 10:23 AM.
Actually, your suppose to set it to whatever you have for your desired idle RPM. The FSM tells you to set it at 850 -/+ 50, but thats because thats what the desired idle RPM table has in it for a stock car.
Last edited by Boosted Tuning; Nov 18, 2012 at 11:03 AM.
Okay. Yeah the one I mention was only for startup. If it idles high like 20-30 seconds after start up then you need to adjust the reg ISCV tables. I also noticed that when you let out the clutch, it stops the high idle issue. So I think it may have to do with the two tables labeled drive and neutral.
Actually, your suppose to set it to whatever you have for your desired idle RPM. The FSM tells you to set it at 850 -/+ 50, but thats because thats what the desired idle RPM table has in it for a stock car.
Actually, your suppose to set it to whatever you have for your desired idle RPM. The FSM tells you to set it at 850 -/+ 50, but thats because thats what the desired idle RPM table has in it for a stock car.
In that case... I'm right on
Jay,
I tried going from 0% to 100% on the ISCV Demand Startup CTS adder. Did literally nothing
I've dropped the ISCV tables a ton and let helped. Car is warm now.. so I'm letting it cool down to try again in a few.
Thanks for the help.
Last edited by R/TErnie; Nov 18, 2012 at 11:25 AM.
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Eric, the ISCV system has trims just like fuel trims. That's the reason for setting the BISS. Goal is to zero out the ISCV learned trims and then set the BISS to whatever RPM is indicated in the target idle RPM table. Best to do it with a fully warmed up car.
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