COBB PROTUNED for 11.5 AFR ECU Slowly leaning car out to dangerous AFR???? Help!!!

[Clipse3GT]

Originally Posted by Hiboost

Keep in mind that if the LTFT's at cruise are "-5.0%" that it is actually running RICH and the car is using fuel trims to remove 5% fuel. This will also be leaning the car out at WOT by 5% which can be a .6 AFR shift (ex 11.5 -> 12.1 AFR).

Yes, I realize this. But what I am trying to figure out is why is it leaning the car out this much, which later in turn is causing knock and timing to be pulled at WOT.

But so far so good, after about 55 miles, we will see after work what the car will be doing.

[LaXGSR]

Originally Posted by Clipse3GT

Yes, I realize this. But what I am trying to figure out is why is it leaning the car out this much, which later in turn is causing knock and timing to be pulled at WOT.

But so far so good, after about 55 miles, we will see after work what the car will be doing.

The only reason LTFT would be leaning out so much would be if your car is running consistently richer than 14.7 during closed loop. It will be interesting if it doesn't lean out anymore after the dealer visit.

[CBRD]

let me know what you find kris,

if there is some issue with the trims it will affect the new map i send, so i want to see what happens, ill make some revisions and see if its something we can fix for you

cb

[Clipse3GT]

Originally Posted by CBRD

let me know what you find kris,

if there is some issue with the trims it will affect the new map i send, so i want to see what happens, ill make some revisions and see if its something we can fix for you

cb

I'm doing some datalogs right now Chad. I have the seen the LTFT go from -.096 to right now -2.449 this is about a 55 miles of driving. So I will continue to datalog to see what is happening overtime. Right now I do not have issues with leaning out while under WOT or any knocking, minus small amounts below 3k rpm, which I think are small bumps in the road or ECU is trying to make the car more fuel efficient.

I will send you some of the datalogs from EVOscan later tonight to see what happening with these logs.

I do however realize that the original map I have from you Chad runs rich while cruising between 60 and 70 on the highway, where the AFR is about 12.8 to 13.6 cruising around 3000 to 3400 rpm. Might be the ECU trying to pull more fuel from the trims to make it 14.7 which in turn is causing my WOT trims to get wacky and get knock and timing retard.

[Clipse3GT]

No I have my car wired up so I have easy access to everything. But I have been being lazy in hooking it up to EVO scan.

Goodness is my LTFT have settled down.... like whaaaaa!!!!

They are -2.4 under cruise conditions and -6.1 at idle constantly. Unless I get out of closed loop. I don't have mode23 turned on, but I do have COBB AP still installed. After another 50 miles they have not changed.

I am not sure what the values should be but this is what they are staying at currently.

I cannot test if the COBB intake, dealer fuel recall, dealer AWC reflash, fuel relay, etc... settled it down. But they are staying constant atleast.

I attached the last few from my long cruises. Used EVOSCAN.

1
http://www.mediafire.com/file/j2ygny...6_13.01.07.csv

2
http://www.mediafire.com/file/4zygly...6_19.15.29.csv

3
http://www.mediafire.com/file/bjum2d...6_19.36.01.csv

[Clipse3GT]

Well I put the COBB intake back one and started datalogging. Here is what is happening. The fuel trims are slowly moving towards a negative after about a 40 minute drive.

Looks like something is up with the tune and needs a tune up.



Here is a bit after I pulled into the parking garage. The trims downed to almost -5%.




Here are LOGS from EVOSCAN.

Log 1
http://www.mediafire.com/file/z5mmji...7_20.40.09.csv

Log 2 - PIC 1
http://www.mediafire.com/file/mzrxmy...7_20.43.37.csv

Log 3- PIC 2
http://www.mediafire.com/file/fo2ijz...7_21.20.09.csv

[CBRD]

Kris,

odd how the trims were close to zero here, but after a 1.5 months they are off...

ill make some corrections and send you the ecuflash map

we will get you back to square one

cb

[Clipse3GT]

I dunno I always run Shell 93 octane. Only thing I can think Otherwise winterized fuel started coming into play.

Edit: Or somehow the elevation change over 300 mile distance. Not sure...

Thanks CBRD you guys are fantastic! Thank you for all the help!

[GST Motorsports]

Some data for for people that like data

I had a 10 on the dyno last night with DW 1000cc injectors. I've tuned a bunch of them at this point, they work well.

Anyway. I was messing around with how much AFR change I would see with LTFT changes.

Car was set for 11.0 AFR at 0.3212 whatever LTFT

with a 2.0 LTFT it ran 10.7 AFR

with a 2.4 LTFT it ran 10.6 AFR

with a -1.5 LTFT it ran 11.2 AFR

Just some data, I also always error on the additive LTFT side if anything so it richens up, not leans out.

Personally I think the AFR sways with LTFT are a bit too sensitive. I know Tephra is (might be?) working on ways to either turn this off (so it acts like Evo 8's and 9's) or just reduce the sensitivity.

- Bryan

[LaXGSR]

Originally Posted by GST Motorsports

Some data for for people that like data

I had a 10 on the dyno last night with DW 1000cc injectors. I've tuned a bunch of them at this point, they work well.

Anyway. I was messing around with how much AFR change I would see with LTFT changes.

Car was set for 11.0 AFR at 0.3212 whatever LTFT

with a 2.0 LTFT it ran 10.7 AFR

with a 2.4 LTFT it ran 10.6 AFR

with a -1.5 LTFT it ran 11.2 AFR

Just some data, I also always error on the additive LTFT side if anything so it richens up, not leans out.

Personally I think the AFR sways with LTFT are a bit too sensitive. I know Tephra is (might be?) working on ways to either turn this off (so it acts like Evo 8's and 9's) or just reduce the sensitivity.

- Bryan

Thanks for sharing! I've seen my LTFT jump as much as 2% on a single day on a completely stock car. Currently it's a bit over 3% and I'm seeing black smoke out the back when I do a 3rd gear WOT pull again (just like stock). I suspect my AFR is back in the 10.7-10.8 range instead of 11.0 or so. Do you have any observational data on how rich the AFR is typically when you start to see black smoke again? When I tuned it to 11.0, I had no black smoke. Need to get the wideband back on the car...

[finald]

What should the AFR be normally?