Tephra v7 9653 thottle hang

[Evo_Kid]

Originally Posted by mrfred

Not sure if I'd want to find these tables for all these ROMs. If I can get further verification that the two tables the OP mentioned fix the problem (e.g., someone using 88590015), then I can find those for other ROMs.

yeah, thats fine. Im not really interested in having all the tables, only the ones the OP mentioned fix the problem.

Thanks

[house_of_senate]

Originally Posted by simple_lancer

Don't fiddle with the Idle stepper lookup table.
It just makes the rev hang happen at a lower rpm, but it still persists.

The reason why there is rev hang, is there is a table that adds a LOT to your idle demand (the vertical axis on the idle stepper lookup table) and causes the stepper position to go really high.

The tables I used to completely erradicate throttle hang were under the "ISCV Control" category:

- ISCV Demand RPM Adder [rpm > 4500, load > 170, speed > 12 mph]
- ISCV Demand RPM Adder (Moderated by Baro, IATS) (FFFF6EA8) (sub_204B6) [sub_1EFC0]

These two tables add up to 100% on top of your idle demand percentage and makes the lookup value much higher in the idle stepper lookup table.

Zero these two tables out, and log your iscv steps in evoscan.
You'll notice instead of going up to 120 or so when you accelerate hard, the iscv steps will only go up to around 70 instead, which will not induce rev hang. The iscv steps will also decay very quickly, since it won't reach such a high value like before. I haven't noticed any reduction in idle quality or part throttle driveability.

You may have to play with your Decel Fuel Cut Delay tables as well, but I don't know what the difference is between tables 1, 2, 3, and 4 are. I just made all my tables the same values as the ones in table 2 (this one has the lowest values and is the same as table 4).

Sorry for the long explanation, but it kind of makes it hard without pictures!

This post has a wealth of info on how the idle speed control system works.
ISCV control system disassembly

Go MrFred you are a legend!

I only have one rpm adder table on 88590015, Did I miss one?

[logic]

There's three of them, they're not all listed together though; I made the same mistake. There's two listed together, then farther down is the other one you're looking for.

[EvoIan]

Just my little addition... I remember reading something about this when the 05's first came out... of course it was for emmisions reasons Funny thing is that as soon as I switched from to the 0006 rom, the throttle hang seemed to diminish if not disappear completely?? Maybe I screwed something up ha

[house_of_senate]

Heres one for ya, about 1 out of every 20 flashes my car will completely stop the revhang. COMPLETELY, until I need to change something and have to flash it again.

[Mitsiman]

If anyone can help I have a customer with the 9860014 and it has horrendus throttle hand, actually causing it to hit the rpm limiter and continue boosting when you take your foot off the throttle when driving hard. Its actually quite dangerous.

Apparently it wasn't too bad until it was reflashed by some other firm.

Can anyone provide me with a modified XML / Def file to solve this? I tried playing with the ISC Look up table which made a minor improvement but not to any significance, and the changes only caused it to stall when the air conditioning was turned on.

[tnt1106]

Originally Posted by mrfred

Not sure if I'd want to find these tables for all these ROMs. If I can get further verification that the two tables the OP mentioned fix the problem (e.g., someone using 88590015), then I can find those for other ROMs.

^ will test this after work tonight as I am down to 2 issues with my car on 015.

Throttle Hang above 3500 when mid to full throttle (then lifting)

A slight "blurb" when very light throttle (think normal highway driving), then lifting the car "stutters" and goes way rich for a second before returning to 14.7 afr.

Will report back.

BTW

Where could I find those decel fuel cut tables for 88590015 ? I only have 1 table listed in my rom. Thanks

Originally Posted by house_of_senate

Heres one for ya, about 1 out of every 20 flashes my car will completely stop the revhang. COMPLETELY, until I need to change something and have to flash it again.

I could swear this is true for me as well but I have flashed so many times hard to keep track..

[travman]

Originally Posted by tnt1106

Where could I find those decel fuel cut tables for 88590015 ? I only have 1 table listed in my rom. Thanks

<table name="Decel Fuel Cut Delay #1" category="Fuel" address="3d6e" type="2D" level="1" scaling="uint8">
<table name="Engine Load" address="6fc6" type="X Axis" elements="7" scaling="Load"/>
</table>

<table name="Decel Fuel Cut Delay #2" category="Fuel" address="3d82" type="2D" level="1" scaling="uint8">
<table name="Engine Load" address="6fc6" type="X Axis" elements="7" scaling="Load"/>
</table>

<table name="Decel Fuel Cut Retard" category="Fuel" address="3da2" type="2D" level="1" scaling="Timing">
<table name="Engine Speed" address="6b7a" type="X Axis" elements="10" scaling="RPM"/>
</table>

<table name="Fuel Limp Table" category="Fuel" address="31ab" type="3D" level="1" swapxy="true" scaling="uint8">
<table name="TPS" address="6fc6" type="X Axis" elements="7" scaling="Volts16"/>
<table name="Engine Speed" address="6fb2" type="Y Axis" elements="5" scaling="RPM"/>
</table>

[tnt1106]

Originally Posted by travman

<table name="Decel Fuel Cut Delay #1" category="Fuel" address="3d6e" type="2D" level="1" scaling="uint8">
<table name="Engine Load" address="6fc6" type="X Axis" elements="7" scaling="Load"/>
</table>

<table name="Decel Fuel Cut Delay #2" category="Fuel" address="3d82" type="2D" level="1" scaling="uint8">
<table name="Engine Load" address="6fc6" type="X Axis" elements="7" scaling="Load"/>
</table>

<table name="Decel Fuel Cut Retard" category="Fuel" address="3da2" type="2D" level="1" scaling="Timing">
<table name="Engine Speed" address="6b7a" type="X Axis" elements="10" scaling="RPM"/>
</table>

<table name="Fuel Limp Table" category="Fuel" address="31ab" type="3D" level="1" swapxy="true" scaling="uint8">
<table name="TPS" address="6fc6" type="X Axis" elements="7" scaling="Volts16"/>
<table name="Engine Speed" address="6fb2" type="Y Axis" elements="5" scaling="RPM"/>
</table>

Thanks Trav!!

[MR Turco]

thanks trav, i have been looking for those

[travman]

Originally Posted by MR Turco

thanks trav, i have been looking for those

Yeah I forget what thread they were in but Mattjin posted them a while back....

[MR Turco]

Originally Posted by travman

Yeah I forget what thread they were in but Mattjin posted them a while back....

i must have had theoriginal definitions, or wrong ones. The values made no sense and i couldn't find any updates.

[fostytou]

Very interesting that those tables are both about twice as high in the IX... although we don't really know how the values are being used/modified by the ECU.

[mrfred]

I've been working my way through the fuel routine and plan to take a look at the decel fuel cut tables soon.

[fostytou]

Originally Posted by mrfred

I've been working my way through the fuel routine and plan to take a look at the decel fuel cut tables soon.

Cheeky Monkey You are always a step ahead of the game!