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Old May 18, 2008, 05:40 PM
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ecuflash guru'sand anyone else (fuel trims)

Hi. So I need some help.
I've gotten my fuel trims at idle to be 0%+1% but my cruising trims are at -12.5%. Mitsulogger reads -13%. I have been dicking with the latencies and it doesn't change. I wasn't making huge changes so maybe that's it but I can't seem to get the cruising trims in check.

I have PTE1000cc's and here are my data...

Injector scaling 770

Voltage
4.6875
7.03125
9.375
11.7188
14.0625
16.4062
18.6768

MS
3.24
2.04
1.392
1.008
0.888
0.648
0.144

I noticed that when I change the 14v MS, that most determines idle...I have no idea which ones determine cruise trims because it doesn't change at all. This morning, when I was messing around with the latencies, the cruising trims were going closer to 0% but always shot negative again after a while even though I don't change anything. I need some help. What do you guys do to correct the cruising trims?

I've also noticed that changing the 16 and 18v latencies determine start up and idle. It doesn't seem like changing the 4, 7, and 9v MS columns change anything. Should it? Maybe it's just my car?

Last edited by RedLanEVO; May 18, 2008 at 05:51 PM.
Old May 18, 2008, 06:02 PM
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770 for 1000cc's? That seems insanely low to me but I could be very wrong here. I was thinking closer to 850-915 would be your scaling. Did you make sure your scaling was dead-on with your stock injectors before you did the swap by any chance?
Old May 18, 2008, 06:05 PM
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My cruising trims were in check before I swapped the injectors. I had 750cc RC injectors before. After my build, the idle trims were whacked. I had decided to throw in some 1000cc. I had is at 812 then I changed it to 870 and then 770. I didn't notice anything in the trims change. Honestly.
Old May 18, 2008, 06:34 PM
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No trims change from 870 to 770??? That makes no sense.
Old May 18, 2008, 06:39 PM
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It's the truth
Old May 18, 2008, 06:47 PM
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If i'm not mistaken, the way it's done is:
1- use the scaling to fix the cruise trims
2- play around with the latencies for the idle trims
Old May 18, 2008, 07:00 PM
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In other threads, it's the other way around. Confusing.
Old May 18, 2008, 07:04 PM
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Originally Posted by MalibuJack
You never scale your injectors to be "perfectly sized" you always scale to be slightly smaller than their rated size, on my car, I would get my cruise fuel trims in check with the scaling, then get the idle fuel trims in check with the Voltage Latency settings.. That should put you at the right scaling.. (It should be roughly 15-25% smaller than the rated size of the injector FWIW)
From this thread:

https://www.evolutionm.net/forums/sh...ight=injectors
Old May 18, 2008, 07:59 PM
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Yup, RTFM
Old May 18, 2008, 08:34 PM
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770 way too low for 1000cc
Old May 18, 2008, 08:44 PM
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Originally Posted by RedLanEVO
I had decided to throw in some 1000cc. I had is at 812 then I changed it to 870 and then 770. I didn't notice anything in the trims change. Honestly.
Your long term trims won't immediately change. If you want to see the immediate change to your trims when changing scaling or latency, look at your short term trim. Eventually, when you meet the right conditions, your STFT will be transferred over to your LTFT, so that the STFT is averaging 0.

I can absolutely guarantee that your trims changed going from a scaling of 870 to 770. You just were looking at the wrong data and didn't give the long term trims enough time to adjust.

We can suggest better settings, but we need the following info:

1. A log of idle with STFT and LTFT Lo. Airflow Hz wouldn't be a bad idea either.
2. A log of cruise with STFT, LTFT Mid, and Airflow Hz.


Eric
Old May 18, 2008, 09:05 PM
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Originally Posted by l2r99gst

We can suggest better settings, but we need the following info:

1. A log of idle with STFT and LTFT Lo. Airflow Hz wouldn't be a bad idea either.
2. A log of cruise with STFT, LTFT Mid, and Airflow Hz.


Eric
Also, to be most certain that the trims are current and accurate, its best to let the car idle for MORE than 16 minutes so it updates the long term fuel trims before you start logging the data. Same for the cruise logs. Take a cruise for more than 16 minutes and then start logging. Its not 100% necessary but I like to let the ECU get as close as it can get on its own before I start any scaling adjustments.
Old May 19, 2008, 05:47 AM
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OK will do.
Old May 19, 2008, 05:52 AM
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Originally Posted by razorlab
770 way too low for 1000cc
Not really true for what I've seen with the PTE's. Mine are scaled to 731 and I get -2 Low and -4 Mid.

RedLanEVO, try my scaling and latency that I posted in the "Injector Scaling" thread.
Old May 19, 2008, 06:02 AM
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I did try your scaling. Your latency values don't work with my PTE's. It barely starts up with your scaling and latencies when I use your data as my base starting point.


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