Can't Stabilize AFR - Log Included

[tmaiorca]

After making a DIY Boost leak test, I hooked it up and pressurized the system. Found a small leak coming from the O ring of the MAF. I still had an old MAF from my MS6 so I swapped em' out and I didn't feel it anymore.

Started her up, idled her for a bit, then did a couple small pulls. The LTFT's are shit because I've driven 100+ miles on a leak, but the boost peaked at 18.17 (surprisingly) and the STFT's look good. AFR's though...wtf? Does this indicate there's still a leak somewhere? And thankfully.....HPFP looks good

Only mods are JBR CAI, JBR TIH, Cobb AP v2, S-OTS tune.

Thanks err'body

[[R]usty]

Did you unhook the battery after fixing the leak to reset the trims?

[sheston]

Didn't see the log

[Dommo14]

*looking for a log* where it at doe??

[tmaiorca]

Originally Posted by [R]usty Did you unhook the battery after fixing the leak to reset the trims?

For the logs purposes, no and I should have. I reset the battery / ecu after the log unfortunately.

Originally Posted by sheston Didn't see the log

Yep...im retarded. Didn't upload it and Im at work atm. Will post when i get home. Or even a new one since i reset the ecu / battery after unhooking it to reset trims.

[tmaiorca]

Originally Posted by sheston Didn't see the log

Hur yah go.

[g00s3y]

Considering your LTFT's are still staying around +20 after the reset, I would say you still have a leak.

[ANITIX87]

You need to log many more parameters (throttle pedal position, timing, WGDC, load, etc) so that we can really know what's going on, but none of this seems terribly unusual for part-throttle driving. Slight changes in commanded throttle will lead to big changes in AFR along with other potential factors like A/C compressor kicking on, etc. It's possible something's wrong, but it's just as likely everything is fine. Posting your map might help shed some light so we can compare actual AFR to commanded AFR.

[tmaiorca]

Originally Posted by g00s3y Considering your LTFT's are still staying around +20 after the reset, I would say you still have a leak.

Appreciate the look-over. I'll see if I can do another boost leak test and check all the clamps, etc.

Originally Posted by ANITIX87 You need to log many more parameters (throttle pedal position, timing, WGDC, load, etc) so that we can really know what's going on, but none of this seems terribly unusual for part-throttle driving. Slight changes in commanded throttle will lead to big changes in AFR along with other potential factors like A/C compressor kicking on, etc. It's possible something's wrong, but it's just as likely everything is fine. Posting your map might help shed some light so we can compare actual AFR to commanded AFR.

Thanks for the input. I'll try and log more parameters next time. In terms of this log however, variables like you said can include A/C compressor, etc. I've come from always being spot on with LTFT's / STFT's, AFR, and boost targets on the 6. Coming to the 3 and now I see all the problems after my intake/tih install, even though I've check it over 1000 times at this point...lol. I'll see if I can post the map when I'm home from work to review everything.

[tmaiorca]

Originally Posted by g00s3y Considering your LTFT's are still staying around +20 after the reset, I would say you still have a leak.

Could it possibly be my Purge Valve? I've been reading different threads and some mention that as a possible cause. Any way to test to see if it's bad?

[08cosmic3]

MAF harness has an issue with some cars. Wiggle the black ground wire on the harness and listen for idle change and monitor for AFR/LTFT fluctuations. New MAF sensor also would need to be re-calibrated.

[Thor Hammer]

Originally Posted by 08cosmic3 MAF harness has an issue with some cars. Wiggle the black ground wire on the harness and listen for idle change and monitor for AFR/LTFT fluctuations. New MAF sensor also would need to be re-calibrated.

MAF sensors themselves do not require calibration. Changing intake size diameter does. Maybe that's what you meant?

[tmaiorca]

Originally Posted by 08cosmic3 MAF harness has an issue with some cars. Wiggle the black ground wire on the harness and listen for idle change and monitor for AFR/LTFT fluctuations. New MAF sensor also would need to be re-calibrated.

Will do when I get a chance. Would this possibly be causing wonky AFR's?

Since its the powerpath intake from JBR, to my knowledge and searching it does not need a MAF calibration. As people have mentioned it, it is not required for this setup, which leads me to believe I've still got a leak/problem somewhere.

[ANITIX87]

Every intake needs a MAF calibration. However, if the JBR was on back when your AFRs and fuel trims were fine, then it won't need a change. Can't hurt to clean the MAF sensor and make sure it's tight (along with all other intake clamps/connections).