KA24DE-T Injector Resize TP Question

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Mon May 28, 2018 7:57 pm

Please try the attached with your board (53F1F)
53F1F_Fix_First_Tune_ClosedLoop.png
53F1F_Fix_First_Tune_ClosedLoop.png (22.6 KiB) Viewed 1133 times
Record another log file showing the jump, when it happens and I can check further
Attachments
53F1F_Fix_First_Tune_ClosedLoop.bin
(32 KiB) Downloaded 22 times

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Wed May 30, 2018 5:22 pm

Mr Matt,

Thank you for working with me on this. I really appreciate it.

Full throttle run:
53F1F_WOT_Run_1to4_Gear.JPG
53F1F_WOT_Run_1to4_Gear.JPG (135.19 KiB) Viewed 1120 times
log:
53F1F_Fix_First_Tune_ClosedLoop_1-4th_Gear_Pull.csv
(37.94 KiB) Downloaded 23 times
Notes:
-At WOT, the issue is not present as in the past however, some strange oscillations can be felt as highlighted in the screen capture (highlit are TP, Injection Time and RPM)

Partial Throttle run:
53F1F_Partial_Throttle.JPG
53F1F_Partial_Throttle.JPG (126.35 KiB) Viewed 1120 times
Notes:
- The issue is still there and can be felt. Seems like when the engine is lugged or light throttle, the issue is worse (shifting from 2nd to 3rd quickly at a low RPM or releasing throttle and lightly applying it again while in gear).
- Looking at the log, the step is almost time based, as if it is a count down counter somewhere before injection is restored.
- The issue seems worse when the engine is cold.

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Wed May 30, 2018 5:23 pm

Log for partial throttle run:

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Sun Jun 03, 2018 8:02 am

Looking more through the logs I was surprised to find that the "Injection Time" and "Injector Duty Cycle" are not a derivative of each other (aka Injection Time and Duty Cycle slopes/graphs are often a bit different than each other).

It seems like the AFR follows more closely to the Duty Cycle and not Injection Time. Now Im trying to wrap my head around how you can vary injection time and duty cycle of PWM output. Seems like the ECU is continuously varying the pulse width and the frequency/quantity of pulses per second, as it doesnt make sense to have 5ms injection time at 50% Duty Cycle vs 5ms injection time at 10% duty cycle, unless you vary n-pulses per second.

Ex1 5ms Pulses at 10% Duty Cycle = 10 x 5ms Pulses in 1 Second

Ex2 5ms Pulses at 50% Duty Cycle = 50 x 5ms Pulses in 1 Second

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Tue Jun 05, 2018 4:58 pm

Duty cycle is just a simple calculation which takes injection time and RPM. So the variance you see may involve RPM. Will be looking into this soon. Thanks for the updated logs

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Fri Jun 15, 2018 6:37 pm

- The issue is still there and can be felt. Seems like when the engine is lugged or light throttle, the issue is worse (shifting from 2nd to 3rd quickly at a low RPM or releasing throttle and lightly applying it again while in gear).
Logs do not show AFR so I am unable to determine if the loss in power where the problem happens is due to AFRs, timing, boost or combination

The oscillation is happening because of the initial drop in RPM which affects TP, then affecting injection time. It is not due to the initial problem, but another separate issue where you get the initial drop in RPM triggering the oscillation

Calculations are TP = RPM/MAF(VQ) x K
Inj time calculated from TP x enrichments x fuel map

As the MAF voltage increases, the oscillation smooths out

These notes based on (1-4th gear pull log)

Initial:
09.250: RPM 3525, MAF 3.5V, timing 20 deg, inj 10.1ms

09.344 RPM drops to 3075, MAF same
=> TP increases, resulting inj time increasing 12.33ms, timing hits last column 18 deg BDTC

0.9443 RPM increases 3425, MAF increasing at same rate
=> TP increases further, so does inj time, timing same

0.9547 RPM drops and continues but smaller steps


Try some stuff here:
Keep your fuel values the same for the last two columns, because it is fluctuating between them. Is this a turbo or non turbo setup? Appears you are using around 740CC injectors?

Same for the timing (in the meantime), last three columns set to 17 degrees

See if it does the same thing then. Why is the RPMs dropping initially after acceleration?

06.547: We see a big drop in timing from 18 to 8 deg BDTC. This appears knock related maybe? Try disable knock feedback in the interim to see if that drops pulling timing like that
- Looking at the log, the step is almost time based, as if it is a count down counter somewhere before injection is restored
Those oscillations are a result of RPM decreasing whilst MAF is slowly building, and it then affecting injection time. Flatter maps should not repeat this issue. Normally turbo setups have flat fuel maps at top end, since as TP increases, so does injection time so you don't need to 'step' the maps up. Larger injectors have flatter maps compared to smaller injectors (740CC will have 1/2 values of that compared to 370CC fuel map)
- The issue seems worse when the engine is cold.
Cannot comment on that without comparing both

Let me know how the above goes

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Fri Jun 22, 2018 3:01 pm

Try some stuff here:
Keep your fuel values the same for the last two columns, because it is fluctuating between them. Is this a turbo or non turbo setup? Appears you are using around 740CC injectors?
This is a Non-Turbo KA24DE with a SR20DET T28 Turbo fitted to it (Basically NA ECU being tuned for Turbo). The Injectors were 275CCs which I upgraded to Subaru 550CCs.
53F1F_Fix_Rev1.bin
(32 KiB) Downloaded 15 times
This bin contains the following:
-I flattened out the Fuel Map
-Resized KConst to use the whole Fuel Map and Timing Map
-Adjusted TIM for fueling (i think it still off, as my "Estimated AFRs" do not match the actuals in the high load areas)
-Pulled in all the changes you had me try in the previous 3 Pages of this thread

Issue is still there.

I did logs of Partial and Full throttle for your review which both include AFR measurements.
53F1F_Fix_Rev1_Full_Throttle.csv
(53.64 KiB) Downloaded 18 times
53F1F_Fix_Rev1_Lean_Partial_Throttle.csv
(136.09 KiB) Downloaded 15 times
The full throttle run, fueling seems off as the numbers in the fuel map do not match the numbers measured, even though at cruising everything is around 14.7-15.1 and the Fuel Trims are near 0s.

The partial throttle still has the step, even though TPS and MAF measurements seem flat. Check out the Short Term Fuel Trim right at the edge of each step. Happens 99% of the time

I really hope we can figure this out soon.

Thank you for the help
Last edited by iyarovoy on Fri Jun 22, 2018 3:21 pm, edited 1 time in total.

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Fri Jun 22, 2018 3:03 pm

Issue is still there.
Lean_Partial_Throttle.JPG
Lean_Partial_Throttle.JPG (210.63 KiB) Viewed 1013 times

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Wed Jul 04, 2018 3:49 am

I may have narrowed down the map that changes this behavior.

"Sync RPM Factor" in expert view seems to change characteristics.

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Wed Jul 04, 2018 10:49 am

Those logs look a lot better than before, but still leaning to 16:1

Okay, does that sync table take away that lean spot we are seeing?

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Wed Jul 04, 2018 11:22 am

Matt wrote:Those logs look a lot better than before, but still leaning to 16:1

Okay, does that sync table take away that lean spot we are seeing?
It happens significantly less, and typically now at throttle tip-in it goes pretty rich, to ~15.3 then back to 14.7 like its supposed to. At very light throttle, it might do it, it might not.

If you could play around with this table on the bench and characterize its effects, that would be very big help! It might be throttle based or RPM based, or the delta-RPM(derivative aka change in RPM) based or deltaTPS (rate of TPS change) or both.

I am attaching a bin that I have been working with. I am viewing nistune in Expert Mode. I copied every map that is under the "Throttle Enrichment" section from the B13 SR20DE bin, as they are very similar Bins and use the same MAF between the SR20DE and KA24DE. I then started copying back the KA24DE enrichment one at a time until I stumbled on one that makes the issue come back.
Attachments
53F1F_Fix_Rev3.bin
(32 KiB) Downloaded 15 times

iyarovoy
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Re: KA24DE-T Injector Resize TP Question

Post by iyarovoy » Wed Jul 18, 2018 10:40 am

iyarovoy wrote: If you could play around with this table on the bench and characterize its effects, that would be very big help! It might be throttle based or RPM based, or the delta-RPM(derivative aka change in RPM) based or deltaTPS (rate of TPS change) or both.
Any updates on this? Just curious if you had time to put this on the bench yet.

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Thu Jul 19, 2018 9:44 am

Sorry missed this post. Will have a look

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Fri Jul 20, 2018 12:06 pm

You could try richening up columns 41-68 if this is a turbo application, since running lean
InjTime_vs_AFR.PNG
InjTime_vs_AFR.PNG (30.56 KiB) Viewed 822 times

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Re: KA24DE-T Injector Resize TP Question

Post by Matt » Fri Jul 20, 2018 12:07 pm

Here we see a lean area but the injection time (orange) is steadily increasing, so that part does not make sense
Lean_spot.PNG
Lean_spot.PNG (20.52 KiB) Viewed 821 times

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