Low Timing and hesitation during cold start

[tephra]

mine is exactly how GST posted...

Keep in mind it is a percentage for interpolation to the coldstart maps.. not a % of the actual timing value...

[Hiboost]

Originally Posted by tephra

mine is exactly how GST posted...

Keep in mind it is a percentage for interpolation to the coldstart maps.. not a % of the actual timing value...

Hmm mine looks like this:

-40 0%
-40 100%
-40 100%
-40 100%
-40 100%
-40 0%
-40 0%
-40 0%

Not sure if it is worth testing still, I would rather find the right table before mucking with unknown values.

As far as percentage for interpolation that is confusing me a bit.

If (42*)+ (-30*) = 12* at 100%, what would 50% or 25% be then?

[tephra]

oops - axis updated in post above...

[billedoc]

hmm good thread, im sub'd to this thread

[Hiboost]

Originally Posted by tephra

oops - axis updated in post above...

That works, will test on my next cold start!

[SiC]

I had the same problem after changing injectors/cams. I just learned how to drive avoiding this RPM/load area when the engine was cold I'll test this out and see how it goes.

[coevolve]

great work guys....subscribed

[Hiboost]

Drum roll...

The car had a wonderfull 40* timing during cold start and was driving SMOOTH as ever just like it was fully warmed up. Thanks Tephra and GST for pin pointing this so quickly!

The only thing is Mitsu may have placed that there to warm the cat for emmissions purposes so anyone still running one may want to try reducing the use of the tables only partially to see if there is balance between smoothness and heating up the cat on cold starts.

[tephra]

Did you just reduce the % in that little table?

I will probably just make 34 degC like 75% and 50 degC like 0%...

So I will still have cold start, but just for shorter time...

[coevolve]

hiboost/tephra can you give a comprehensive review of what you did? (not comprehensive in length necessarily)
What .xml code did you use?
Which map?
What changes...etc

Thanks guys, awesome work!!!

[Hiboost]

Originally Posted by tephra

Did you just reduce the % in that little table?

I will probably just make 34 degC like 75% and 50 degC like 0%...

So I will still have cold start, but just for shorter time...

I went to 0% for now and will add some retard back for the colder weather that will eventually bear down on New York State. There is probably a happy medium ground for percentages that will work for colder weather.

What looks odd to me though is the retard was kicking in at 120-140 F coolant temps but according to the chart it should only have kicked in that table from 18 F to 93 F for 100% and then tapered to 0% by 122 F.

-32 C = -26 F
-8 C = 18 F
7 C = 45 F
20 C = 68 F
34 C = 93 F
50 C = 122 F
62 C = 144 F
77 C = 171 F

hiboost/tephra can you give a comprehensive review of what you did? (not comprehensive in length necessarily)
What .xml code did you use?
Which map?
What changes...etc

Thanks guys, awesome work!!!

I'll post some screenshots after work unless Tephra beats me to it, everything you would need is in the posts though.

[GST Motorsports]

Originally Posted by Hiboost

Drum roll...

The car had a wonderfull 40* timing during cold start and was driving SMOOTH as ever just like it was fully warmed up. Thanks Tephra and GST for pin pointing this so quickly!

The only thing is Mitsu may have placed that there to warm the cat for emmissions purposes so anyone still running one may want to try reducing the use of the tables only partially to see if there is balance between smoothness and heating up the cat on cold starts.

Awesome, glad tephra could find it so quickly.

This will help a ton when you get cams as well as they make the cold starts worse with the timing retard.

[coevolve]

Originally Posted by Hiboost

I went to 0% for now and will add some retard back for the colder weather that will eventually bear down on New York State. There is probably a happy medium ground for percentages that will work for colder weather.

What looks odd to me though is the retard was kicking in at 120-140 F coolant temps but according to the chart it should only have kicked in that table from 18 F to 93 F for 100% and then tapered to 0% by 122 F.

-32 C = -26 F
-8 C = 18 F
7 C = 45 F
20 C = 68 F
34 C = 93 F
50 C = 122 F
62 C = 144 F
77 C = 171 F



I'll post some screenshots after work unless Tephra beats me to it, everything you would need is in the posts though.

Thanks man. The "axis" change post was the only thing that confused me a bit...
screenshots would be awesome. When did you start experiencing this low throttle condition? My X is stock save the tuning that i've been learning. My current part throttle is quite fine.

[GST Motorsports]

Ok here is the table:



and here is the code used for getting it:


evo10base.xml:
<scaling name="Percent255" units="%" toexpr="100*x/255" frexpr="255*x/100" format="%.0f" min="0" max="100" inc="1" storagetype="uint8" endian="big"/>

<table name="Percent Low Temp Timing Trim vs Coolant Temp" category="Timing" type="2D" level="2" scaling="Percent255">
<table name="Engine Temp" type="Y Axis" elements="8" scaling="Temp"/>
</table>

52680015:

<table name="Percent Low Temp Timing Trim vs Coolant Temp" address="56170">
<table name="Engine Temp" address="610e0"/>
</table>


A big thanks to Tephra.

[tephra]

no problemo