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Old 09-15-2021, 09:47 AM   #26
guciodog11
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Quote:
Originally Posted by 86Dreams View Post
I knew one guy that sorted this out by adjusting the intake temperature compensation table.

Your observing a hunting idle right?

I would get this on my 02 after tgv deletes on a usdm ecu. then when I had a jdm motor i had a jdm ecu and i would get a hunting idle on the usdm ecu but not the jdm.

I never quite figured it out but always suspected that part of the problem is hard coded into the way the feedback control with AF correction works. essentially what I think happens is at cold start the AF correction routine destabilizes itself and so it over corrects one way then back the other way then back the other way and so on until its warmed up. for me tapping the throttle to break it out of the warm up phase would put it into a regular idle.

This is part of why I have the opinion that I do about scaling the MAF in OL.


But a log of more than anything might be revealing.
personally id like to see RPM, MAF, AF Sensor 1, AF Sensor 1 Current, AF Sensor 1 Resistance, CL/OL Switch, Final Fueling target, coolant temp, intake temp, MAP, injector pulse width

this thread has some interesting discussion
https://www.romraider.com/forum/view...p?f=15&t=13088
I'll get a log today, and hopefully a video also showing the wideband.
It's cyclical with a period of about 40 seconds. Starts strong at 1200 RPM and semi-rich, then leans out (17+) and rpms drop to 500 or so. After a few seconds AFR bounces back to rich, along with RPM's for 20 seconds.

I'll try to mess with disconnecting the MAF on startup, that's the last variable that I can imagine that might be causing the problem. The scaling was not redone for 10 years (car wasent driven either) and I put in a few other mods since then, nothing intake related though.

Interestingly, the O2 takes a while to warm up, even when the engine is at operating temp. I can shutdown and restart, and itll take 60 seconds for CL to kick in again. I monitored o2 resistance after shutdown and it goes to 255 literally seconds after the motor stops turning. I'm assuming this is normal?

Looking through that thread now, my fluctuations are wayyy worse, but his seem to be in CL too, not just warmup OL. Also his fluctuations have a much shorter period.

I did redo my entire PCV system to add a catch can, already checked it for leaks. Nothing is vented to air at least.
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Last edited by guciodog11; 09-15-2021 at 09:53 AM.
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Old 09-16-2021, 09:05 PM   #27
guciodog11
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Finally got around to do some datalogging. Turns out the pins in my ECU won't come out so ill have to find some other way to log the wideband ugh.

Here's the log from cold and completely off, to CL kicking in.
https://drive.google.com/file/d/1qsc...ew?usp=sharing

And a video of the same log:
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Old 09-16-2021, 09:06 PM   #28
guciodog11
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Finally got around to do some datalogging. Turns out the pins in my ECU won't come out so ill have to find some other way to log the wideband ugh.

Here's the log from cold and completely off, to CL kicking in.
https://drive.google.com/file/d/1qsc...ew?usp=sharing

And a video of the same log:
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Old 09-17-2021, 09:19 AM   #29
86Dreams
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Quote:
Originally Posted by guciodog11 View Post
Finally got around to do some datalogging. Turns out the pins in my ECU won't come out so ill have to find some other way to log the wideband ugh.
[/url]
youre open source so if your wideband has an RS232 connection you can get a dongle to convert that to USB and then log it in tandem to the ECU parameters from RR.


That video is pretty much what I expected. If you can log that with RR then the front O2 is good enough. i always noticed that the departure from accurate for the front O2 is somewhere around stoich +/- like 1.0 afr gasoline (13.7<14.7<15.7).


if you havent wired the blue and green test connections to a switch then do so, it will make your life a lot easier.

then start testing things in the most meticulous and tedious way possible. log every test.
logging and testing will be hard because its a cold start issue, once you test one change then you have to wait quite a while for the engine to cool so you can test another change.


so what could fix this?
Smoothing stoich afr range of the front O2 sensor calibration
Warm up enrichment settings.
Intake temperature compensation tables
MAF calibration around this load area.
Engine Load compensation manifold absolute pressure table.

Youre using MerpMod right? I unfortunately havent ever looked through a merpmod rom. If I get time I will dig around in one to see if any other tables jump out at me.

Looking at carbery there is a MAF /SD blending table, so that is also something you should check, to make sure SD is not being applied for now.

Im sure there are other places to look.

personally Id start with IAT table, then MAF, then front O2 smoothing.

Last edited by 86Dreams; 09-17-2021 at 09:38 AM.
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Old 09-17-2021, 11:57 AM   #30
guciodog11
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Awesome, Thanks for the quick reply!

I was planning on wiring the wideband analog output to the TGV sensor input on the ECU, I jerry rigged it through the engine bay and it worked fine with RR with some xml editing, but I wanted a neater solution (direct to ECU instead of console->through firewall->connected to TGV harness). I bought a set of pin removal tools, hopefully they'll fit the tiny ecu connector holes.

Already have the green connectors on a switch, best mod I've done so far!

Merp just adds additional tables like LC/FFS and most importantly SD/MAF/Hybrid stuff, I left that all unmodified for now. I threw in the required files needed to open merp'd ROM's if you want to take a look, however a bunch of tables only show up in Ecuflash for some reason.


When you mention modding those tables, how do you even go about it? I woudn't know where to start! just start varying values up and down, reflashing and seeing if it makes a difference? By smoothing do you mean just reducing the peaks and minimizing the differences between values? Sorry I'm new to any of this stuff. Anything past what I've already done with rescaling MAP and other basic stuff is out of my comfort zone without more knowlege/reading.

O2 scaling I think i can pull off some forum, but scaling IAT without a known reference might be hard for me.

The warmup enrichment values are stock, I'll try to mess with them a bit.

And this issue isn't exactly always at bone cold idle. Restarting at operating temp shows the same problems, CL doesn't kick in until about a minute in. I'll try to get another log at operating temp, just a a quick restart.

Forgot to log without the MAF being connected, but from what I remember the same will occur

Thank you!

Last edited by guciodog11; 09-17-2021 at 12:03 PM.
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Old 09-17-2021, 02:13 PM   #31
86Dreams
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maybe go straight for the front O2 then

stock 04 scaling below
Code:
-1.2999999523162842	-0.8699999451637268	-0.4699999988079071	-0.13999998569488525	0.0	0.09999999403953552	0.23999999463558197	0.38999998569488525	0.5299999713897705	0.6399999856948853	0.7399999499320984	0.7399999499320984	0.7399999499320984
11.151419949531554	12.165516757965086	13.179309529066085	14.193103176355361	14.7	15.20689594745636	16.220689594745636	17.234481489658354	18.24827513694763	19.262068784236906	20.275860679149627	20.275860679149627	20.275860679149627
you could shoot from the hip and move the values around 14.7 closer to that number. sho change 15.2 to 15.1 and 14.19 to 14.4, something like that.
you might want scale a line and then shift its slope thorugh the intercept at 14.7 to make that region smooth.
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Old 09-17-2021, 06:45 PM   #32
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I am fairly new to open source tuning myself but i would not start by scaling sensors for a cold start issue. Start changing your idle compensations by the same scale you changed your injector scaling. For example , if you increased your injectors by 20%, you need to reduce your idle timings by the same percent. It took a while to get my idle correct.
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Old 09-17-2021, 06:53 PM   #33
benflynn
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Hes scaling sensors cause his intake has changed
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Old 09-17-2021, 07:00 PM   #34
FierceWRX
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'Otherwise the car has been tuned for a TD06-20G, FMIC, Helix 880's and a K&N SRI'

I take that as it has already been tuned for those. correct me if i am wrong
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Old 09-17-2021, 09:44 PM   #35
guciodog11
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Quote:
Originally Posted by 86Dreams View Post
maybe go straight for the front O2 then

stock 04 scaling below
Code:
-1.2999999523162842	-0.8699999451637268	-0.4699999988079071	-0.13999998569488525	0.0	0.09999999403953552	0.23999999463558197	0.38999998569488525	0.5299999713897705	0.6399999856948853	0.7399999499320984	0.7399999499320984	0.7399999499320984
11.151419949531554	12.165516757965086	13.179309529066085	14.193103176355361	14.7	15.20689594745636	16.220689594745636	17.234481489658354	18.24827513694763	19.262068784236906	20.275860679149627	20.275860679149627	20.275860679149627
you could shoot from the hip and move the values around 14.7 closer to that number. sho change 15.2 to 15.1 and 14.19 to 14.4, something like that.
you might want scale a line and then shift its slope thorugh the intercept at 14.7 to make that region smooth.

I know i'm new at this, but why would I change the o2 scaling? All my issues occur during OL, when the O2 is not in play at all. I just checked my map and the o2 scaling is identical to stock.

Turns out 4 connector ECU harnesses cannot be depinned, so i'll splice into the harness to get wideband logging into the TGV input port.
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Old 09-17-2021, 09:51 PM   #36
guciodog11
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Quote:
Originally Posted by FierceWRX View Post
I am fairly new to open source tuning myself but i would not start by scaling sensors for a cold start issue. Start changing your idle compensations by the same scale you changed your injector scaling. For example , if you increased your injectors by 20%, you need to reduce your idle timings by the same percent. It took a while to get my idle correct.
All my idle comps are identical to stock, I don't think my tuner went that far with the tune years ago. It was mostly a street tune that took 2ish hours or so.
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Old 09-17-2021, 09:55 PM   #37
guciodog11
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Quote:
Originally Posted by benflynn View Post
He's scaling sensors cause his intake has changed
Just checked and my MAF scaling is stock! This is interesting, might be the source of all my problems.

Last edited by guciodog11; 09-17-2021 at 11:02 PM.
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