I am at a loss as to why this is going on. Here is what happens:

I flash the car on Sunday and do some logs the AFR is as it should be. You can see it in the chart on top in the image below. I am very satisfied with the tune. Monday morning on my way to work, I do a log with the SAME flash but the AFR changes and the AFR is about 1 full point richer in some areas. you can see this in the image in the bottom in the image below.

I thought that is was Lean Spool related. So, this morning I flash the car with a non-lean spool flash and do a long and the AFR is where it should be. I drive to work park the car and then on the way back from work do another log and the AFRs are RICH again.

When I get home I flash the car back to the flash that I used on Sunday and do some logs and the AFR is back to normal. If the trend holds, then the AFR tomorrow morning will be rich again.

I checked for exhaust leaks and there are none. I am using t-bolt clamps on the pipes.

What is going on here? I need

 

Do you still have the ebay filter on? Intake temps the same on both logs? Looks like up top once you are moving and getting more airflow both logs are almost the same.

 

are you runing the same boost with both flashes? when there is more boost your afrs richen
i also see that the 2nd log your on a higher load colum more time then the first log

 

I am now running a drop-in K&N. The intake temps did not change a lot.

When I first flash the ECU and do a log the AFR is where it should be. The very next day with the same flash, the AFR goes rich from peak boost to about 6000 rpm. As you observed, after 6000 rpm the AFR goes back close to where it should be.

For some reason the AFR goes rich between 2500-6000 rpm when I shut off the car and let is sit over night or a few hours.

 

Where are your fuel trims at? If you're getting positive long term trims after driving for awhile that could cause you to be richer than when you tuned it with out having fully developed fuel trims.

 

The boost, timing and AFR is the same. The tables are logged on the SAME flash, but I get a richer AFR in one than in the other. Both the 220 and 240 load colums have the same AFR target, so the load is not an issue.

Why does my AFR gets messed up when I park the car and let it rest for a while? Why do I get good AFR on the same flash one time and a rich AFR the next time????

 

the way it has happend to me for example is i do a first log and the afrs are fine but when the car starts to get hot i start to see lean afrs cause iam hitting less boost on my gauge maybe i have gotten heat soaked or something...
but i have seen that i get a richer afr when its cold at night cause iam hitting more boost the difference has been 0.5points on the afrs.
have you logged your boost is it that same on both logs?

 

I have not logged my LTFT. What should they be on a car like mine with a TBE, dtop-in and 22 psi of boost? Should I log STFT?

 

nj you should also log coolant temp the hotter they are the richer afrs become

 

Ideally, you want your LTFT to be as close to 0 as possible. STFT will be constantly changing, but it is used to develop the LTFT. Whenever you reflash the ECU, you're resetting the fuel trims. So if you datalog immediately after flashing, then you're logging without having developed fuel trims. This can be a hassle if you end up developing large correction fuel trims after a few drive cycles.

 

mixmaster correct me if I have it wrong

wouldn't think the trims have any effect on open loop. a bad latency would, but wouldn't that show up as soon as he flashed?

I've always assumed the trims only worked in closed loop as they try to correct for afr off 14.7.

nj, there must be another dog in the hunt.

 

You are correct. I went out and logged LTFT and it was @ ZERO during the entire drive to and from the logging site as well as @ WOT. The good thing is that after I flashed the ECU @ 3 pm PST, the AFR is still the same when I logged @ 7:40 pm PST. The AFR did NOT become richer like before. Tomorrow, I will do a log on my way to work and see if the AFR stays the same. I am keeping my fingers crossed.

 

I always log the coolant temps. I keep them between 175-188 while logging. If the coolant temps cross into 190 (fan kicks in), then I do not log.

 

on logworks it would be short and mid term trim.
I don't think you get much in the way of response from long term trim. Mine has never moved that I know of. (so you may not be out of the woods yet)

 

So I should log STFT and MTFT. Which one should stay @ zero? According to mixmastermatt the STFT changes a lot, so should I be keeping an eye on the MTFT?