Nistune strange injection time issue

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Nistune strange injection time issue

Postby ilya240sx » Thu May 17, 2018 9:14 pm

Quick overivew of the car:
- S13 KA24DE
- T28 Turbo (wastegate pressure ~5-6 PSI)
- Stock KA24DE MAFS
- Subaru STI 550cc Injectors (1050uS latency)
- Looking to get 200HP
- S13 ECU with Type3 Feature Pack board

Im having an issue where the injection time is slow to catch up with the fuel map. When doing full throttle run, the AFRs stay lean until, what seems to be a random point, then step down and get to where they are supposed to be (see picture). At that "step" point, the car finally feels like it has power. Looking back at the log, you can see the injection time doing a massive step up (orange line), at which point AFRs richen up and get to where they are supposed to be (green line) and the car comes alive.

Has anyone ever encountered this?

Thank you

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Log and Tune:
S13_FP_Tune_Rev2.zip
My Tune
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Log_File.zip
Log File
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Re: Nistune strange injection time issue

Postby p00t » Thu Jun 07, 2018 7:35 pm

What RPM does it happen? Check your TTPMAX settings versus the logs. Put that whole table to 255 and test again. You can change it later if you want.

Your knock maps are zeroed but your knock sensor is ON. Your fuel knock map is super lean... copy the fuel map between primary and secondary. I get the 0 timing so you know when you hit knock, but its not pleasant when you are driving in traffic or something and it occurs.... copy your primary map and take 4 degrees out or something like that. You can still see you had knock with your logs.
Last edited by p00t on Thu Jun 07, 2018 7:42 pm, edited 1 time in total.
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Re: Nistune strange injection time issue

Postby p00t » Thu Jun 07, 2018 7:37 pm

Also consider using an N60 maxima MAF. It will give you more stable AFR versus the G70 one and it is less restrictive.
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Re: Nistune strange injection time issue

Postby ilya240sx » Mon Jun 25, 2018 8:32 am

p00t wrote:What RPM does it happen?

It happens at any RPM when apply throttle. Any load I apply at any RPM causes the AFR to go lean and then back to normal. This is an S13 KA24DE which has the SCV Butterflies removed. Maybe the ECU is programmed to pull Fuel to account for the SCV at partial throttle?


p00t wrote: Check your TTPMAX settings versus the logs. Put that whole table to 255 and test again. You can change it later if you want.

TP Max is set well above any TP I have ever seen in the logs. I set it to 255 all across the RPM range and the Issue is still there.

p00t wrote:Your knock maps are zeroed but your knock sensor is ON. Your fuel knock map is super lean... copy the fuel map between primary and secondary. I get the 0 timing so you know when you hit knock, but its not pleasant when you are driving in traffic or something and it occurs.... copy your primary map and take 4 degrees out or something like that. You can still see you had knock with your logs.

Im using a Feature Pack Nistune board that has the Knock Timing and Fuel Maps removed for the S13 KA24DE, which is why it probably looked funny when viewing my bin using a non FP address file.

It seems like this is an ongoing issue I keep finding in older posts across all Nissan Forums and no one has an answer for, including the guys who made nistune, they are stumped by it as much as I am...
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Re: Nistune strange injection time issue

Postby p00t » Wed Jun 27, 2018 9:09 pm

ilya240sx wrote:
p00t wrote:What RPM does it happen?

It happens at any RPM when apply throttle. Any load I apply at any RPM causes the AFR to go lean and then back to normal. This is an S13 KA24DE which has the SCV Butterflies removed. Maybe the ECU is programmed to pull Fuel to account for the SCV at partial throttle?


When I look at your logs the switching point to go back to rich happens at the same RPM in two parts of the trace. What RPM is this red line at?
Image

So here are my suggestions at this point:

[*]Try a different base ROM (an sr20de one if possible).
[*]Try a 300zx n62 MAF
--->there are likely Alpha-N type functions that think the high maf voltage at low-mid RPM is a bad MAF. The bigger MAF has a lower voltage at those points and doesn't trip this logic.
---> Just trying to help because I know from my experience with an n62 MAF I have never encountered this in KA or SR tunes. I have also not encountered this with sr20 map and stock g70 maf
[*]Wait for NISTUNE to fix this... :angry-cussingblack:
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Re: Nistune strange injection time issue

Postby ilya240sx » Thu Jun 28, 2018 11:23 am

Thank you for the response and helping me out on this!


p00t wrote:When I look at your logs the switching point to go back to rich happens at the same RPM in two parts of the trace. What RPM is this red line at?
Image


It happens at different RPMs, and I think the RPM are determined by the TPS voltage. Less throttle == lower RPM switch point
p00t wrote:So here are my suggestions at this point:

[*]Try a different base ROM (an sr20de one if possible).
[*]Try a 300zx n62 MAF
--->there are likely Alpha-N type functions that think the high maf voltage at low-mid RPM is a bad MAF. The bigger MAF has a lower voltage at those points and doesn't trip this logic.
---> Just trying to help because I know from my experience with an n62 MAF I have never encountered this in KA or SR tunes. I have also not encountered this with sr20 map and stock g70 maf

Can I use an SR20DE bin on a KA24DE???

p00t wrote:[*]Wait for NISTUNE to fix this... :angry-cussingblack:

Sounds like you have experience :)

Im going to try the 23432 different fixes mentioned in this thread viewtopic.php?f=36&t=41156&hilit=part+throttle
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Re: Nistune strange injection time issue

Postby ilya240sx » Tue Jul 03, 2018 9:43 am

No Luck with the 0x0200 Map fix. That map is the Alpha-N map. It sets the threshold for the TPS voltage at which the ECU jumps to the last column of the Fuel Map. So it causes really rich conditions for a turbo vehicle when driving around casually hence why they say you should set this map to max values to never trigger this conditions.

Still at a loss.
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Re: Nistune strange injection time issue

Postby p00t » Wed Jul 11, 2018 8:32 pm

When I look at your tune in tuner pro I see the knock sensor box checked. I am not sure if Nistune handles that differently but it seems odd to me. Do you have another tune with the knock feature enabled or with the secondary maps in place?
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Re: Nistune strange injection time issue

Postby ilya240sx » Fri Jul 13, 2018 6:26 pm

p00t wrote:When I look at your tune in tuner pro I see the knock sensor box checked. I am not sure if Nistune handles that differently but it seems odd to me. Do you have another tune with the knock feature enabled or with the secondary maps in place?


Yeah I have the knock sensor checked but I do not have any flags in the ignition map set for knock sensing. The check box works as a master switch which I have enabled but no cells selected where the knock monitoring should happen.

With the turbo installed, the KA knock sensing is too sensitive. The ECU would pull timing when there were knock indications on the spectrogram.

I have my ignition set to 17 degrees at 5 PSI and the ECU was pulling an extra 8 degrees out because it thinks there was knock.

Does anyone know if a R20DE bin on a KA24DE will work? like a B13 SE-R Bin on a S13 KA. They share a common MAF.
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Re: Nistune strange injection time issue

Postby p00t » Fri Jul 13, 2018 7:55 pm

When I look at your primary ignition map there are areas flagged for knock detection. I must be missing something else?

I'm only bugging you about this because the issues fits if it is at least still using the fuel knock map, which you have zeroed (14.7:1 AFR). This would make it lean until knock went away or you went out of the knock cells with TP or RPM.
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Re: Nistune strange injection time issue

Postby ilya240sx » Fri Jul 13, 2018 8:13 pm

p00t wrote:When I look at your primary ignition map there are areas flagged for knock detection. I must be missing something else?

I'm only bugging you about this because the issues fits if it is at least still using the fuel knock map, which you have zeroed (14.7:1 AFR). This would make it lean until knock went away or you went out of the knock cells with TP or RPM.


I understand your concern. I am using the Nistune Feature Pack which has the Knock Maps converted for Flex Fuel control and Launch Control. The feature pack Nistune Software now just pulls define-able degrees of timing anytime knock is detected in the "Knock Enabled" ignition cells instead of jumping to a different map. The feature pack Nistune does nothing with the fuel map when knock is detected.

I think the issue is related to the fact that with a turbo, the air transients are much faster so the ECU is not setup to respond to the transients fast enough. It has to be one of the enrichment tables that would require many hours of trial and error.
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