Is it based on coolant temp?

 

Yup

 

Hey guys, Was it ever confirmed which of these definitions is correct for the 88590015 Rom ?.
Or

 

The tables that are in the first post are correct and work. On my car they do anyways.

 

Bumping this for some more info ...

I've recently found that the idle speed w/ AC on (88590015 ROM) seems to just follow the desired idle RPM set using the tables posted in this thread. This doesn't seem right to me as the idle w/ AC on should be higher ... it could be that the idle w/ AC on is set at 960 RPM stock (the same as my current desired idle RPM). I'll play with it some more this evening if I find time.

Also relating to the AC ... it seems that adjustments to the ISCV adjustment for AC on doesn't make much of a difference. With the AC on the RPM drops to about 600 when I decel with the clutch in. Adjustments to the ISCV table dont seem to help this as they did with the neutral/drive tables.

I've also noticed that some of the VIII definitions include optional tables such as a temp-based ISCV adder and idle RPM for increased IAT. Has anyone found these tables for the IX ROM? With how my car has been acting in traffic recently, I know these tables must exist ... idle increases about 100 RPM in traffic and the rev down responds like the ISCV tables are off (bounces).

If anyone could help with this I would really appreciate it. It may help other as well who tune for drivability. Once these tables are found/corrected I'll post a full idle/ISCV definition with only the tables that work to help avoid confusion with idle tuning.

 

Okay, going back through this thread some of these questions may have been answered and I just missed/forgot about them ... Updating first post.

 

Any updates TB?

 

Not so much for updates, but some tuning suggestions ...

1) the desired idle w/ AC on is useless on the '05 and '06 models. the target idle w/ AC on seems to be the same as the normal desired idle RPM. I haven't tested the desired idle RPM drive to see if it's the same as well.

2) There is a very small window for tuning the desired ISCV tables. Changing the value by as little as 2 or 3 increments can cause near stalls or hanging above desired RPM. Once you get close, only adjust ISCV by 1 increment at a time.

3) Bumping values in the first 5 rows or so of the 3D stepper map can help rough-in idle and reduce stalling. Again, make small changes and keep the ramp smooth. Keep changes consistent across the columns as the desired ISCV tables take care of cold start.

 

In preparation for an ECUFlash xml update, I finally went through the idle subroutines this evening. After I test out a few things tomorrow, I expect to have updated more correct target idle tables. Haven't done anything with ISCV tables yet.

 

This is great news as always thanks Mr. Fred

I have been reading and was going to create a thread about AC or maybe even heater on idle control. Def. ac the car idles but even stock had a hard time with idle. All the posted tables do not work.

 

I've got it pretty much worked out. Just need to verify a few things, and I'll post up revised tables.

 

Here are the updated target idle tables for the USDM Evo 9 88590015.

gunzo's idle tables should be deleted. The original idle table should also be deleted.

I think I've got somewhere between 16-20 hours of time into figuring out these tables. My head hurts. There are two target idle RPMs for when AC is on. There are four factors that determine when one AC idle is used over the other. Its too hard to concisely explain these factors, so I'm not going to try. Suffice to say that both values are used when the AC is on during normal driving, so you may want to tinker with both. I wasn't able to figure out exactly what MIVEC conditions trigger the use of "Target Idle For Off-Normal MIVEC". There is a bunch more stuff to disassemble to figure it out, and I'm not sure its worth the effort. I may work on that more tomorrow.


----
<table name="Target Minimum Idle" category="Idle" type="2D" address="3d24" level="1" scaling="RPM8">
<table name="Engine Temp" type="Y Axis" address="70c2" elements="8" scaling="Temp"/>
</table>

<table name="Target Idle When IAT > 205F" category="Idle" address="1e30" type="2D" level="1" scaling="RPMTarget">
<table name="Conditions" type="Static Y Axis" elements="2">
<data>AC Off</data>
<data>AC On</data>
</table>
</table>

<table name="Target Idle For Off-Normal MIVEC" category="Idle" address="223e" type="1D" level="1" scaling="RPMTarget"/>

<table name="Target Idle RPM With AC On #1" category="Idle" address="1470" type="1D" level="1" scaling="RPMTarget"/>

<table name="Target Idle RPM With AC On #2" category="Idle" address="146c" type="1D" level="1" scaling="RPMTarget"/>
----

Nov 29: Found more info on High IAT idle and updated definitions.

 

Thanks again Mr. Fred I will be putting these in tomorrow and testing after my alignment. The temp. table explains why car changes idle at higher temps.

A stab in the dark but any possibility that the Mivec relationship has anything to do with throttle hang above 3200 rpm and real bad at 4000 up? Why does the clutch switch cause rpm to return to normal? Oh well drifitng off topic.

Good stuff.

 

I just tested this with my 272's at idle and seems to be working great. The logged target idle matched the cells in the defaul idle tables, and the logged rpms hovered around the target. I turned the AC on and it didnt even hickup, whereas before idling or soming to a stop, id have to kill the air.

Ill give it a thorough road test this weekend.

I did find one problem however. When I kicked on the heater, the idle dropped below 500rpms...just about to stall for a good 5 seconds before raising back up, any thoughts?

Another question I have, since I had the cams installed, my warmup idle is ~2k, is this something that can be adjusted, or something I'll have to live with?

 

Did the logged target idle change when you kicked on the heater? I suspect the answer is no. Sometimes what the idle does during transient engine loading conditions is due more to the stepper value.