Maf for testing

[bokehmon]

Hey NW crew - I've installed my edelbrock supercharger, but have been having some weird fuel trim issues (+/-30), and believe that it may be a sensor issue.

I've smoke tested the intake for leaks, but haven't found any. I've also replaced the o2 sensor with no discernible difference, which leads me to believe that the maf or wiring may be faulty (can't see/feel any leaks in the exhaust either)

I've got a 2014 brz - not sure if there's a difference between years and mafs though.

Does anyone in the larger Seattle area (I'm in Lynnwood) have a maf that I could borrow for testing?

[NoHaveMSG]

I’m too far to help though I have a suggestion. I would log the car at a steady state. Look at what the maf voltage is reading. If the car is idling for a minute and the maf voltages are all over the place it’s probably the maf.

[bokehmon]

Originally Posted by NoHaveMSG

I’m too far to help though I have a suggestion. I would log the car at a steady state. Look at what the maf voltage is reading. If the car is idling for a minute and the maf voltages are all over the place it’s probably the maf.

Thanks! They're between 1.0 and 1.7~, which looks OK. g/s are also within spec.

I'm actually seeing the issues around 2700 rpm at steady state (stft goes to +30, and ltft goes to +40 max). It's definitely concerning.

I'm going to go back to stock header and try to eliminate things one by one. I'm wondering if i just have a dirty injector or something.

[NoHaveMSG]

Originally Posted by bokehmon

Thanks! They're between 1.0 and 1.7~, which looks OK. g/s are also within spec.

I'm actually seeing the issues around 2700 rpm at steady state (stft goes to +30, and ltft goes to +40 max). It's definitely concerning.

I'm going to go back to stock header and try to eliminate things one by one. I'm wondering if i just have a dirty injector or something.

What are you using for a base tune? Does it gradually build stft/ltft or does it spike?

[bokehmon]

Originally Posted by NoHaveMSG

What are you using for a base tune? Does it gradually build stft/ltft or does it spike?

I actually had it tuned @ Drift Office, but they've also created the same tune for other cars and have no issues - sounds like I have something weird going on with my car.

Here's a 60~MPH cruise - you can def see the LTFT and the STFT spiking

https://datazap.me/u/bokehmon/log-16...&data=31-34-35

[NoHaveMSG]

Originally Posted by bokehmon

I actually had it tuned @ Drift Office, but they've also created the same tune for other cars and have no issues - sounds like I have something weird going on with my car.

Here's a 60~MPH cruise - you can def see the LTFT and the STFT spiking

https://datazap.me/u/bokehmon/log-16...&data=31-34-35

The AFR is bouncing around target so it is trying to compensate, I would guess that likely O2 is reading correctly if that is the case. Beyond what I can help with

[bokehmon]

Originally Posted by NoHaveMSG

The AFR is bouncing around target so it is trying to compensate, I would guess that likely O2 is reading correctly if that is the case. Beyond what I can help with

No worries - really appreciate the help!

I think I'm going to slowly remove variables, hopefully I won't have to re-install the supercharger.

[JoeS]

Did you get this sorted out? I have MAF sensor that you can borrow, but you'll need to either pick it up today or wait until the 10/15. I'm in Renton.

[FR-S2GT86]

Originally Posted by JoeS

Did you get this sorted out? I have MAF sensor that you can borrow, but you'll need to either pick it up today or wait until the 10/15. I'm in Renton.

Ode to Renton

[bokehmon]

Originally Posted by JoeS

Did you get this sorted out? I have MAF sensor that you can borrow, but you'll need to either pick it up today or wait until the 10/15. I'm in Renton.

Just saw this - probably too late to come pick up, unless you're there late!

I didn't - i just checked the header for leaks - looks fine, so probably some thing top side (maf, vacuum leak[?])

Messaging you my # if you're in Renton still - I can drive down today.

Update: got an appointment with the Drift Office guys - they're taking a look at it on Saturday. Thanks everyone!