TouringBubble

iTrader: (2)

I was adjusting my desired ISCV tables just a sec ago and realized something ... The defined "Desired ISCV Initial Step Position with AC Off-Neutral" table is actually the desired idle RPM table. Adjusting this table changes the values in the real "Desired Idle RPM" table we defined a few months back and affects the desired idle ROM value in the logs as well.

Does anyone know the correct address for the ISCV table?

inco9nito99

iTrader: (90)

So you're saying that by adjusting the "Desired ISCV Initial Step Position w/ AC off-Neutral" you can adjust idle RPM on IX's? Effectively?

RazorLab

iTrader: (8)

Or you can use the def that was found awhile back:

<table name="Actual Desired Idle RPM" category="Idle" address="3d24" type="2D" scaling="RPM8">
<table name="Engine Temp" address="70c2" type="Y Axis" elements="8" scaling="Temp"/>
</table>

TouringBubble

iTrader: (2)

Yes ... that table references the same address as the actual idle RPM table Razor mentions above. If you have them both defined you can adjust one and watch the values in the other change.

So, we had the idle table in the ROM the whole time, it was just defined incorrectly ... now it might be useful to find the real ISCV table. I've made some changes today that I'm planning to test ... we might have full ISCV control with the 2 other tables that are already defined.

Basically, the ISCV tables seem to be baseline values to reach the desired idle RPM. If the value is off, the ECU corrects the ISCV value up or down to match the desired idle RPM. Logging the desired idle RPM and the ISCV values can tell you exactly where the ISCV values need to be.

TouringBubble

iTrader: (2)

It's also starting to look like the AC on/off tables are reversed ... but I'm not sure of that yet. The actual ISCV values seem to follow more closely to the AC on map, but changes to the AC off map do affect idle.

anyway ... if anyone would like to take on the task of checking those ISCV tables and maybe getting the correct definitions for AC off neutral, AC off drive and AC on it would be helpful. I'd go for it but I have no idea where to start ...

gt420hp

iTrader: (5)

What are the suggested numbers to change (increase) for rpm's dropping?

Here is what my map looks like now.

TouringBubble

iTrader: (2)

Table #2

77 - 21
82 - 18

Table #3

77 - 43
82 - 36

inco9nito99

iTrader: (90)

Apparently incresed idle timing helps as well with the dip.

1slowevo

iTrader: (96)

what does these 4-8 units of increase mean? I am trying to find out how to deal with that dip in idle when coming to a stop as well.

dbsears

iTrader: (37)

Could this correct a high idle that hangs when the car is cold? Until my car warms up my idle hangs around 2000rpm for the first minute or two.

Inprogress

iTrader: (30)

^ I believe thats normal. You are in a region with some cold temps, but may be the others more knowledgeable will chime in.

gt420hp

iTrader: (5)

I made the changes as suggested. I do see an improvement, you can see the rpm's drop but they go back to normal much faster without the car stalling. I am still seeing an issue when sitting in traffic, going up an incline. If I give it more gas to move forward, it wants to stall, but if I give it just the smallest amount of throttle to move forward, usually it is staying in the 700 rpm range.

This definately improved the rpm behavior, but not a perfect fix.

TouringBubble

iTrader: (2)

If you'll notice, the ISCV tables are temp based. With low coolant temps, the ISCV values are higher, causing increased idle speed. However, the ISCV tables don't determine the actual warm up idle speed ... the idle tables define the target and the ISCV tables define the baseline ISCV amount to reach that target. But, the ECU can adjust the ISCV on the fly.

I have had a little luck adjusting the ISCV tables for better drivability from a cold start, but the cold idle RPM lies in a combination of the ISCV tables and idle tables, and possibly a little in the timing map.

dbsears

iTrader: (37)

I guess let me go into more detail. Stock flash it starts up and idles strong at 1600 then drops in a couple seconds to 1200-1300. I can put the clutch in and take off and it comes back down like it should. Whereas with my tune I start the car and its shoots up to about 2200 and hangs there until the car it warm. You take off and it still hangs up at 2200 when coming to a stop. It also starts bucking anything below 2000rpm until it warm. It is rather quite annoying and sometimes I don't even run my tune unless I'm at the track. Again its perfectly normal on my stock flash.

Btw I also noticed that changing my mivec to a less agressive JDM RS helped since there less timing down low. I also changed my timing back to the stock 5degrees in the low load cells. Seemed to help a little but it still does it.

JohnBradley

iTrader: (30)

I have logs that show the timing, alpha and beta as well, and the car is on a totally different ignition map until it warms up. It seems that you have a 50/50 chance of this happening to you as soon as you run a different map. I have steadily removed everything that is a tune, chopped down timing, dropped the ISCV and desired idle and it will do it for the first 30-60 seconds the car is running.

I never had an issue on the 13, but when I switched to the 15 it showed up. There is a 5* difference when the car is warming up. It seems that once the car hits the min temp for full boost that it goes to the normal maps. Well at least when it gets close to it, I have seen it go back to normal sooner. I think IAT also has something to do with the modifier.