Huge Difference in Long Term Bank 1 & 2 Trims
11-03-2015, 09:38 PM
#1
Burning Brakes
Thread Starter
Huge Difference in Long Term Bank 1 & 2 Trims
So I datalogged my LS3 that I've been having sputtering/hesitation issues with and found there is a huge difference in fuel trims bank 1 vs. bank 2 - over 30% difference. Bank 2 is getting maxed out then just flat lining at +32%.
11-04-2015, 08:42 AM
#2
Burning Brakes
Thread Starter
All work and tuning was done by ECS - ECS 2200, Small Blower Cam, Alky with SD tune, ARH long tubes with high flow cats. Recently the car would get choppy (not the cam) on idle and acceleration, more like a hesitation. It would happen on and off, but now it is there 100% of the time. The car feels like it has no power there is sometimes a burning smell from the mufflers. I used DashCommand on my iPhone to log it. Those were the only things that stood out to me.
11-04-2015, 08:46 AM
#3
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The time you have spent making posts you could have had the exhaust lowered and checked the cats already. 
11-04-2015, 08:56 AM
#4
Burning Brakes
Thread Starter
Haha hey watch it! I had the collector bolts removed and noticed that you guys tack welded the 2 halves of the X pipe!!!
PS...I can't work on the car at work lol
PS...I can't work on the car at work lol
Last edited by KevinD92; 11-04-2015 at 08:56 AM.
11-04-2015, 02:19 PM
#5
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St. Jude Donor '15
That's a pretty graph you've got there!
11-08-2015, 10:36 PM
#7
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St. Jude Donor '13-'14-'15
The most common issue for a large split in LTFT's between sides is an exhaust leak---Even a small one can make the difference as much as 20%---beyond that being that car is newish- next I would suspect a bad 02 circuit or a fuel line obstruction on the fuel rail
11-09-2015, 11:39 AM
#8
Burning Brakes
Thread Starter
I messed around with the injector harness clip on cylinder 6 as the injector wasn't ticking and the car is fine now! The injector is now ticking as well
11-09-2015, 12:29 PM
#9
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St. Jude Donor '15
11-09-2015, 03:40 PM
#11
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St. Jude Donor '15
Not unusual for them to fluctuate some.. ideally they'd stay right around zero of course. In general mine seem to go a little more negative as the weather cools down and more positive when it's warmer. I'd have to see a log to really say if it's an issue
If you're running meth then it's hard to screw it up too bad, lol.. the octane rating is high enough that you should avoid knock regardless with meth going
If you're running meth then it's hard to screw it up too bad, lol.. the octane rating is high enough that you should avoid knock regardless with meth going
Last edited by schpenxel; 11-09-2015 at 03:41 PM.
11-10-2015, 03:10 PM
#12
Burning Brakes
Thread Starter
I forgot Doug at ECS said the cam would make those numbers unreliable...however I now notice some white smoke and a strong gassy smell coming from the exhaust. It was never like the in the past.
11-14-2015, 10:28 PM
#13
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St. Jude Donor '13-'14-'15
REMEMBER anytime you have a positive fuel trim "just before going to WOT" that % is ADDED to your WOT fueling as well as a lean safety--This could explain your rich smell--However is you have a negative fuel trim the ECM will never subtract fuel at WOT and will lock on a "0" fuel trim
11-15-2015, 07:29 AM
#14
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St. Jude Donor '15
Tuning 101
11-17-2015, 04:26 PM
#16
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St. Jude Donor '15
Without a wideband no one can really say. It's not going to hurt anything just because the fuel trims aren't showing zero. Fuel trims are doing their job and adjusting how much fuel is injected.. in a perfect world they wouldn't have to adjust more than a few percent, but in reality they move around some.
The problem is they can't do much at WOT. Unless you have a wideband there's no way to tell what the AFR actually is at WOT (the ECM can't tell either) so it has no idea whether to add fuel or take away fuel..
The problem is they can't do much at WOT. Unless you have a wideband there's no way to tell what the AFR actually is at WOT (the ECM can't tell either) so it has no idea whether to add fuel or take away fuel..
Last edited by schpenxel; 11-17-2015 at 04:27 PM.