Tephra v7 9653 thottle hang
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From: Tri-Cities, WA // Portland, OR
EvoM Guru
iTrader: (50)
Joined: Mar 2006
Posts: 9,675
Likes: 132
From: Tri-Cities, WA // Portland, OR
Haven't done the flex fuel patch yet. I'm waiting on the v7 final. I've been chasing the fuel stuff in hopes of finding a solution to hard warm starts with my ID1000s.
I initially had somewhat troublesome warm starts as well, but I reduced the fueling in the warm start ranges and it starts pretty well from cold, warm, or hot.
Maybe you have already done that, but just throwing it out there just in case.
EvoM Guru
iTrader: (50)
Joined: Mar 2006
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From: Tri-Cities, WA // Portland, OR
Have you taken fuel out of the appropriate temp ranges for the cranking/running maps? You may just need to take out even more than you expect. An easy test is to start the car with the throttle half way open. If it starts right up, then there was too much fuel.
I initially had somewhat troublesome warm starts as well, but I reduced the fueling in the warm start ranges and it starts pretty well from cold, warm, or hot.
Maybe you have already done that, but just throwing it out there just in case.
I initially had somewhat troublesome warm starts as well, but I reduced the fueling in the warm start ranges and it starts pretty well from cold, warm, or hot.
Maybe you have already done that, but just throwing it out there just in case.
I was going to ask about that as well, but was waiting for what you find. I have a couple of cranking tables listed and was wondering what the conditions were for each, etc.
Hopefully you will post up what you find and then I can take a look at 96530006.
Hopefully you will post up what you find and then I can take a look at 96530006.
This isn't my tuning computer, so I don't have the exact numbers on here, but basically just used all of the tables I had defined for the IPW cranking/starting/running, etc and adjusted the table first for the injector size, then adjusted the warm temps down and the cold temps up (at least for E85, which needs a lot more at the colder temps). I'm still in the process of fine tuning the cold, since it's just starting to get cold here, but so far so good.
But the most troublesome for people seems to be warm starts. If the car starts better with your throttle plate open, then that's a good sign that it's getting too much fuel. So, keep taking out fuel in the cranking/starting tables in that temp range until it starts first time with no throttle input.
But the most troublesome for people seems to be warm starts. If the car starts better with your throttle plate open, then that's a good sign that it's getting too much fuel. So, keep taking out fuel in the cranking/starting tables in that temp range until it starts first time with no throttle input.
Last edited by l2r99gst; Oct 9, 2009 at 05:46 AM.
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.
https://www.evolutionm.net/forums/ec...sassembly.html
Go MrFred you are a legend!
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.
https://www.evolutionm.net/forums/ec...sassembly.html
Go MrFred you are a legend!
Evolving Member
Joined: May 2008
Posts: 346
Likes: 0
From: Dallas, TX
[QUOTE=tnt1106;7589682]^FIXED all and any throttle hang for my IX. I returned ISCV Table to stock then 0'ed out the 2 tables. Thank you!
To fix still:
A slight "blurb or stutter" when very light throttle (think normal highway driving less than 5psi boost), then lifting the car "stutters" and goes way rich (10.xx afr) for a second before returning to 14.7 afr. As if the BOV needs to vent but can't?
To fix still:
A slight "blurb or stutter" when very light throttle (think normal highway driving less than 5psi boost), then lifting the car "stutters" and goes way rich (10.xx afr) for a second before returning to 14.7 afr. As if the BOV needs to vent but can't?
A slight "blurb or stutter" when very light throttle (think normal highway driving less than 5psi boost), then lifting the car "stutters" and goes way rich (10.xx afr) for a second before returning to 14.7 afr. As if the BOV needs to vent but can't?
Evolving Member
Joined: May 2008
Posts: 346
Likes: 0
From: Dallas, TX
so lower the voltage on latencies and lower scaling?
Edit: I changed out my stock IX BOV, for a Forged one with light spring and the effect is more evident. It feels to me as if air is being blow back thru the maf. ( I think this issue started when I went from stock air box to open.) I am going to try stock air box and see.
Last edited by tnt1106; Oct 12, 2009 at 08:10 AM.
Changed the decel fuel cut tables to match those of 94170015 and the throttle hang is still present. It is not as bad, the RPMs fall slowly but the AFRs do not peg lean, they stay around 13-14.
I noticed the same, my car now doesn't hang near as bad, almost 1/2 of a second now, compared to 3-5 seconds before and doesn't go rich much 12-13 AFR then goes to normal. Here are the values I changed:
