Stop your Car Stalling from Clutch in!
EvoM Guru
iTrader: (50)
Joined: Mar 2006
Posts: 9,675
Likes: 132
From: Tri-Cities, WA // Portland, OR
The key though is having the correct tables. As it turns out, the decel fuel cut tables that were posted many years ago are incorrect. They are ISCV control tables. I have the correct tables now and will post them later today.
Having sad all that, IMHO the decel fuel cut tables should only be adjusted after everything else is in good order. Leaking throttle shaft seals would definitely exacerbate the issue. The injectors should also be well tuned and clean. On Evo 9s, it would be beneficial to minimize MIVEC (overlap) in the 10 and 20 load cells up to at least 1500 rpm and maybe to as much as 2000 rpm.
Last edited by mrfred; Sep 13, 2016 at 06:43 AM.
I've got a reasonably good handle on it for my Evo now. The crux of the issue is getting back to a good afr after decel. Since the injectors are off during decel, the intake runners are dry, so extra fuel is needed when fuelling resumes to re-wet the walls. The need to stop the decel is also aided by extra fuel. For my experience, I did not need to touch the ISCV tables. It was all fixed with fuel cut disable. There is an algorithm to add an extra shot of fuel when the injectors are reenabled. Due to my 100 rpm higher-than-stock idle, and probably due to running R2s, I had to raise the decel fuel cut disable by 250 rpm.
The key though is having the correct tables. As it turns out, the decel fuel cut tables that were posted many years ago are incorrect. They are ISCV control tables. I have the correct tables now and will post them later today.
Having sad all that, IMHO the decel fuel cut tables should only be adjusted after everything else is in good order. Leaking throttle shaft seals would definitely exacerbate the issue. The injectors should also be well tuned and clean. On Evo 9s, it would be beneficial to minimize MIVEC (overlap) in the 10 and 20 load cells up to at least 1500 rpm and maybe to as much as 2000 rpm.
The key though is having the correct tables. As it turns out, the decel fuel cut tables that were posted many years ago are incorrect. They are ISCV control tables. I have the correct tables now and will post them later today.
Having sad all that, IMHO the decel fuel cut tables should only be adjusted after everything else is in good order. Leaking throttle shaft seals would definitely exacerbate the issue. The injectors should also be well tuned and clean. On Evo 9s, it would be beneficial to minimize MIVEC (overlap) in the 10 and 20 load cells up to at least 1500 rpm and maybe to as much as 2000 rpm.
Evolving Member
Joined: Mar 2012
Posts: 116
Likes: 22
From: usa
Anyone every figure out the correct tables? I'm on 94170715 and the "clutch-stall" is killing me, almost hit a parked car the other day while turning.
I did find a thread taking about advancing ignition between 500-1000rpm and 20-60 load. Will try that and report if it fixes anything.
.
I did find a thread taking about advancing ignition between 500-1000rpm and 20-60 load. Will try that and report if it fixes anything.
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Newbie
Joined: Mar 2015
Posts: 93
Likes: 1
From: Perth, Western Australia
Anyone able to help me out on this?
Ive got an Evo VII ECU in my Evo 3, new ISC.
RPM drops way too low on clutch in (near stall), I've increased the timing in the low load cells, and bumped the 'desired iscv initial step position" tables up to like 100 steps, and that seemed to fix it.
But now, the idle sits way too high, once the engine heats up, the rpm's climb to 1500, then it cuts ignition to drop them (and repeat).
I have no idea what the hell the problem is :/
Ive got an Evo VII ECU in my Evo 3, new ISC.
RPM drops way too low on clutch in (near stall), I've increased the timing in the low load cells, and bumped the 'desired iscv initial step position" tables up to like 100 steps, and that seemed to fix it.
But now, the idle sits way too high, once the engine heats up, the rpm's climb to 1500, then it cuts ignition to drop them (and repeat).
I have no idea what the hell the problem is :/
Evolved Member
Joined: Oct 2010
Posts: 868
Likes: 23
From: Streets of willow
Anyone able to help me out on this?
Ive got an Evo VII ECU in my Evo 3, new ISC.
RPM drops way too low on clutch in (near stall), I've increased the timing in the low load cells, and bumped the 'desired iscv initial step position" tables up to like 100 steps, and that seemed to fix it.
But now, the idle sits way too high, once the engine heats up, the rpm's climb to 1500, then it cuts ignition to drop them (and repeat).
I have no idea what the hell the problem is :/
Ive got an Evo VII ECU in my Evo 3, new ISC.
RPM drops way too low on clutch in (near stall), I've increased the timing in the low load cells, and bumped the 'desired iscv initial step position" tables up to like 100 steps, and that seemed to fix it.
But now, the idle sits way too high, once the engine heats up, the rpm's climb to 1500, then it cuts ignition to drop them (and repeat).
I have no idea what the hell the problem is :/
Adjust "desired iscv initial step position A.C off neutral" to 30 steps.
Adjust your BISS - [ Base idle screw ] so that car sits at your desired idle rpm.
I hope the AFRs at idle are not in 10s or 11s .
Newbie
Joined: Mar 2015
Posts: 93
Likes: 1
From: Perth, Western Australia
AFRs are fine, what I was finding is that I couldnt get the car to idle below 1000rpm when I activate SAS mode and start playing with the BISS.
Evolved Member
Joined: Oct 2010
Posts: 868
Likes: 23
From: Streets of willow
You have to play with Timing at idle, Isc steps and biss.
If you spend 1 hour doing this , you will be near the desired results.
Newbie
Joined: Mar 2015
Posts: 93
Likes: 1
From: Perth, Western Australia
At the moment Ive got the idle set to 900, but once the car heats up, it wont idle below like 1500, and the idle slowly rises until ignition cut and it drops again.
Going to try with the standard Evo VII ROM and see if anything changes
Did you post these tables up on another thread? I searched but didn't see anything. Thanks man!!!
Newbie
Joined: Apr 2005
Posts: 4
Likes: 0
From: Daly City
ISCV Demand RPM adder table
Hi Simple_lancer,
I know it has been years since you have posted this information, I have recently have the idle problem after changing to HKS cams. I have ECU Flash the original one and I cannot find the "ISCV Demand RPM adder table" that u described. Please point me to it. much appreciated.
I know it has been years since you have posted this information, I have recently have the idle problem after changing to HKS cams. I have ECU Flash the original one and I cannot find the "ISCV Demand RPM adder table" that u described. Please point me to it. much appreciated.
Been experimenting with the ISCV Tables that MrFred kindly found.
I was having stalling issues after putting FIC 1050s in.
The car would want to stall on clutch in, or after lifting the throttle after applying light-medium throttle on high load (like going up a hill slowly).
I have fixed 90% of the stall issue by increasing the values of the 'ISCV Demand RPM Adder*' table!
500 11.8
1000 11.8
1500 11.8
2000 11.8
2500 12.2
3000 13.3
3500 14.5
4000 16.1
4500 17.6
5000 20.0
I made the first 4 values the same, so that the ECU doesn't try and interpolate between two rows and cause your idle to fluctuate.
Also, I've determined the function of some of the ISCV tables so that they have more meaningful names. This is for 96530706 by the way.
The drive tables don't seem to do anything on manual transmission EVOs; they look like orphaned tables from the Jap Spec EVO 7 GTA which is an Auto.
You need to make changes to the tables marked neutral.
The old 'Decel Fuel Cut Delay' tables are actually TPS based ISCV adder tables!
'ISCV Demand CTS Adder #1**' -> 'ISCV Demand CTS Adder AC Off - Neutral'
'ISCV Demand CTS Adder #1b***' -> 'ISCV Demand CTS Adder AC On - Neutral'
'ISCV Demand CTS Adder #1a***' -> 'ISCV Demand CTS Adder AC On - Drive'
One table missing is:
<table name="ISCV Demand CTS Adder AC Off - Drive" category="ISCV Control" address="4296" type="2D" scaling="ISCV_AX2_8">
<table name="Engine Temp" address="6a86" type="Y Axis" elements="8" scaling="Temp"/>
</table>
This table is called 'Desired ISCV intial step position with AC off-Drive' in the original ecuflash xml.
It should be relabelled 'ISCV Demand CTS Adder AC Off - Drive'.
'Decel Fuel Cut Delay #1' -> 'ISCV Demand TPS Adder AC Off - Neutral'
'Decel Fuel Cut Delay #2' -> 'ISCV Demand TPS Adder AC Off - Drive'
'Decel Fuel Cut Delay #3' -> 'ISCV Demand TPS Adder AC On - Neutral'
'Decel Fuel Cut Delay #4' -> 'ISCV Demand TPS Adder AC On - Drive'
Scaling of these tables should be changed to 'ISCV_AX2_8'.
I was having stalling issues after putting FIC 1050s in.
The car would want to stall on clutch in, or after lifting the throttle after applying light-medium throttle on high load (like going up a hill slowly).
I have fixed 90% of the stall issue by increasing the values of the 'ISCV Demand RPM Adder*' table!
500 11.8
1000 11.8
1500 11.8
2000 11.8
2500 12.2
3000 13.3
3500 14.5
4000 16.1
4500 17.6
5000 20.0
I made the first 4 values the same, so that the ECU doesn't try and interpolate between two rows and cause your idle to fluctuate.
Also, I've determined the function of some of the ISCV tables so that they have more meaningful names. This is for 96530706 by the way.
The drive tables don't seem to do anything on manual transmission EVOs; they look like orphaned tables from the Jap Spec EVO 7 GTA which is an Auto.
You need to make changes to the tables marked neutral.
The old 'Decel Fuel Cut Delay' tables are actually TPS based ISCV adder tables!
'ISCV Demand CTS Adder #1**' -> 'ISCV Demand CTS Adder AC Off - Neutral'
'ISCV Demand CTS Adder #1b***' -> 'ISCV Demand CTS Adder AC On - Neutral'
'ISCV Demand CTS Adder #1a***' -> 'ISCV Demand CTS Adder AC On - Drive'
One table missing is:
<table name="ISCV Demand CTS Adder AC Off - Drive" category="ISCV Control" address="4296" type="2D" scaling="ISCV_AX2_8">
<table name="Engine Temp" address="6a86" type="Y Axis" elements="8" scaling="Temp"/>
</table>
This table is called 'Desired ISCV intial step position with AC off-Drive' in the original ecuflash xml.
It should be relabelled 'ISCV Demand CTS Adder AC Off - Drive'.
'Decel Fuel Cut Delay #1' -> 'ISCV Demand TPS Adder AC Off - Neutral'
'Decel Fuel Cut Delay #2' -> 'ISCV Demand TPS Adder AC Off - Drive'
'Decel Fuel Cut Delay #3' -> 'ISCV Demand TPS Adder AC On - Neutral'
'Decel Fuel Cut Delay #4' -> 'ISCV Demand TPS Adder AC On - Drive'
Scaling of these tables should be changed to 'ISCV_AX2_8'.