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Author Topic: Ignition retard on overrun  (Read 1435 times)
KasperH
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« on: October 08, 2019, 04:54:45 PM »

I have fiddled a bit with overrun after i've gotten my car on the road again.
But i just can't seem to retard timing past TDC when fuel is being injected.
As soon as fuel cuts off i can get the timing to indicate 60 degree ATDC(not sure if correct)
I've read the FR and tried all the timing maps and nothing seems to get it past TDC with fuel,
but without fuel there is no problem retarding ignition.
i get a faint nearly inaudible burble and the occasional pop on shifts as it is now,
but nothing really substantial.

So if somebody can point me i the right direction it would be greatly appreciated Cheesy
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KasperH
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« Reply #1 on: October 09, 2019, 10:52:58 AM »

i digged a little deeper, and it seems that KFZWMS wont be used as long as B_sa=1.
« Last Edit: May 09, 2020, 03:07:24 PM by KasperH » Logged
KasperH
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« Reply #2 on: October 10, 2019, 06:45:14 AM »

Might be worth mentioning that im trying to achieve this without modifying KFZWOP.
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KasperH
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« Reply #3 on: May 06, 2020, 12:29:37 PM »

So a little update on my "project".

So after fiddling with this with what little spare time I have
after becoming a farther.
I have come to the conclusion that ignition retard on overrun
can't be achieved without altering KFZWOP.

With that being said, it works as desired with altered KFZWOP.
now I will dive into fuel control on overrun since I'm getting a flat 1.36ms of injection time.
That results in a fat mixture and LOUD far apart bangs, and not the "classic" gargle.

TEMIN seems to have no effect on this, so I might look into trying FKKVS.
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sinnfuly_righteous
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« Reply #4 on: May 06, 2020, 12:44:50 PM »

I appreciate this!! As soon as my f21 turbos show up I'm gonna give it a try.

Sent from my SM-N976U using Tapatalk

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Dejw0089
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« Reply #5 on: May 06, 2020, 02:57:33 PM »

I have fiddled a bit with overrun after i've gotten my car on the road again.
But i just can't seem to retard timing past TDC when fuel is being injected.
As soon as fuel cuts off i can get the timing to indicate 60 degree ATDC(not sure if correct)
I've read the FR and tried all the timing maps and nothing seems to get it past TDC with fuel,
but without fuel there is no problem retarding ignition.
i get a faint nearly inaudible burble and the occasional pop on shifts as it is now,
but nothing really substantial.

So if somebody can point me i the right direction it would be greatly appreciated Cheesy
Maybe you have right about KFZWOP but I have one audi with bad thermostat and no matter what i do with fuel can't past TDC.
Thermostat was fixed so engine temp can rise up and car popping as should.
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KasperH
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« Reply #6 on: May 09, 2020, 02:24:59 PM »

I have found the "WECIFI" function in the "ACIFI" module.

The map "FWEMXT" looks to be a factor of the max allowed fuel between 0 and 1.
It needs CWESWEZ bit 3 set to 1.

i have set the factor of "FWEMXT" to 0.85 from 86.25 degree C,
so in theory it will only allow 85% of the previous fuel to be injected in overrun.
« Last Edit: May 09, 2020, 03:04:38 PM by KasperH » Logged
Dejw0089
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« Reply #7 on: May 10, 2020, 04:44:09 AM »

I have found the "WECIFI" function in the "ACIFI" module.

The map "FWEMXT" looks to be a factor of the max allowed fuel between 0 and 1.
It needs CWESWEZ bit 3 set to 1.

i have set the factor of "FWEMXT" to 0.85 from 86.25 degree C,
so in theory it will only allow 85% of the previous fuel to be injected in overrun.
I see FWEMXT and have set to 0.85 as you but missed set CWESWEZ to 08 so set it too and check Smiley
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KasperH
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« Reply #8 on: May 13, 2020, 09:32:31 AM »

After a couple of days testing to see if any trims would have a influence.
I can conclude that it have had no effect on the overrun,
I still get the same flat 1.36 ms of injection time and have
the same loud, far apart explosion.

Guess it means I have to keep digging  Smiley
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bamofo
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« Reply #9 on: May 13, 2020, 01:48:24 PM »

After a couple of days testing to see if any trims would have a influence.
I can conclude that it have had no effect on the overrun,
I still get the same flat 1.36 ms of injection time and have
the same loud, far apart explosion.

Guess it means I have to keep digging  Smiley


Are you trying to do decel (negative Timing) to get it to gurggle and bang?

Easiest way to do that is write some code on all the overall angle timing lookups and force it to what you want when the conditions are set. Subaru you just set the left hand column and off you go. another thing might be to hook in the cruise control so you can manage when it does it so you dont get pulled over... Lastly if its banging really loud then its still charging the coil fully.. If you share where your at (your rom) we can suggest. I could be wrong to, i am a lot as i learn... but i just worked on a project like this. Guess it depends on what ME your running on.
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Dejw0089
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« Reply #10 on: May 14, 2020, 05:59:37 AM »

After a couple of days testing to see if any trims would have a influence.
I can conclude that it have had no effect on the overrun,
I still get the same flat 1.36 ms of injection time and have
the same loud, far apart explosion.

Guess it means I have to keep digging  Smiley
What to you try to achieve? My car normalny go ATDC when I'm in overrun and pop & bang as should. So what is problem in your tune?
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KasperH
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« Reply #11 on: May 14, 2020, 12:41:01 PM »


Are you trying to do decel (negative Timing) to get it to gurggle and bang?

Easiest way to do that is write some code on all the overall angle timing lookups and force it to what you want when the conditions are set. Subaru you just set the left hand column and off you go. another thing might be to hook in the cruise control so you can manage when it does it so you dont get pulled over... Lastly if its banging really loud then its still charging the coil fully.. If you share where your at (your rom) we can suggest. I could be wrong to, i am a lot as i learn... but i just worked on a project like this. Guess it depends on what ME your running on.

I have timing retard working as desired.
The original goal was to get timing retard without altering KFZWOP.
But after trying everything I could think of,
I gave up and altered KFZWOP and it worked like it should.

Now I'm chasing control of the fuel on overrun,
since from what I can gather from things I've read on different forums
ideally the fuel mixture should be on the lean side to get the classic crackles
and a fat mixture will result in more aggressive and explosive overrun.

And from what I can see, when the car is in overrun the mixture is fat
and the injection time is locked to 1.36ms.

So I'm searching for the module that controls fuel on overrun,
thought I had it for a second but i guess not Smiley
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KasperH
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« Reply #12 on: May 14, 2020, 12:45:31 PM »

What to you try to achieve? My car normalny go ATDC when I'm in overrun and pop & bang as should. So what is problem in your tune?

I want to achieve a overrun that has the "subtle" crackle and occasional pop.
Not a explosion fest that could wake up a neighbourhood  Grin

Timing retards ignition fine now after I altered KFZWOP.
Just doesn't sound like i want it to.

What ECU are you running?
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Dejw0089
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« Reply #13 on: May 14, 2020, 12:58:36 PM »

I want to achieve a overrun that has the "subtle" crackle and occasional pop.
Not a explosion fest that could wake up a neighbourhood  Grin

Timing retards ignition fine now after I altered KFZWOP.
Just doesn't sound like i want it to.

What ECU are you running?
Thanks for ansfer. I'm running On 1ML906032 ECU. My car 1M1 Leon Cupra.
Ok maybe together we find solution.
What timing do you have?
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fukenbroken
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mk4 1.8T AUM


« Reply #14 on: May 14, 2020, 01:54:03 PM »

Kfvakl kfbakl?
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