LTFT(LOW)= -7.351
LTFT(MID) = -3.0361
LTFT(HIGH)= .1008
STFT= 10.10

Running 96531706 rom SD
evo4
Gm 3 bar map
680cc injectors
fuel temp iat

what is my ecu doing.. i know both ltft low and stft should be +-5% but when i adjust the scaling and latency to bring it within that threshold my idle is stable and im seeing 14.6-14.9 on the wideband but as i rev i experience knock(12 counts) and a 18:1 afr with more then 40% throttle. some times it hits 18 some times it goes to 10:1. This is without hitting any boost.
Thanks for the help ....

 

when was the last time you changed your primary o2 sensor? anytime anyone has had erratic results with fuel trims, 95% of the time its a bad o2 or its on its way out. your trims arent bad, bringing your scaling up a tad would fix that, without having to touch your latencies.

 

its funny cause i just purchased that o2 sensor. But i had purchased a cam sensor at the same time which happened to be the reason my car wouldn't start. I will check. thanks

 

Post logs, MAP/VE, RPM/VE tables and fuel. If it were me I would go after your SD tables, but i don't know all of of the background on the car?

 

I don't have any upgrades just a stock evo 4 motor with Delphi 680cc injectors. Running a gm 3 bar map. I will post idle logs in the morning

 

were your fuel trims good before you went over to speed density? if they were then you might want to adjust your RPM/VE and Map/VE tables.

 

idle log

 

map VE
kpa load
10.8504 17.9731
20.1938 46.0969
31.0442 61.4625
40.9904 86.6994
60.8828 100.854
94.941 127.954
119.053 299.956
390.012 390.007



SD RPM VE

75
75
75
75
75
79.6875
100
100
100
100
100
100
100
100
100
100
100

 

Why do you have your VE tables setup like that? At 95kpa (just under 0 boost), you have a load of 130 and at 120kpa (just into boost) you have a load of 300.

 

im new to this and im just trying to understand it. everytime i searched for info it said trial and error. so thats how i got there. let me know what im doing wrong i really want to learn and understand how this works.

 

So from that should i adjust 130 to where i start to see boost in my log.. am i in the right direction ?

 

It's definitely not trial and error. There's a method to the madness.

I would suggest reading through jcsbanks' whole thread entitlted 'SD: first test success' or somethng similar.

He goes through the entire SD patch and tuning process. If you read that thread and understand it, you will have a better grasp on the concept and will be able to tune your SD tables better.

On a side note, is there any reason why you are running SD and not the MAF in the first place? Just curious because if you did have a MAF and logs from that, it can be used to establish a starting point for your SD tables.

But if you are sticking with SD, I would suggest really understanding what's going on and how to tune it first. There are number of threads that go into pretty good details, but that one I gave you should be a good starting point.

 

thanks