Trying to troubleshoot some fuel trim values that are higher than normal on my wife's '12 Fit and was hoping someone with a scan tool or torque pro could share some MAF data from their car with me for a comparison. I'm looking for:

-MAF reading (in g/s) at idle & 55mph flat cruising speed

-Long term & short term fuel trims associated with those MAF readings.

I would greatly appreciate any help from the community with this.

Thanks guys
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I've got torque pro. can do over the next few days prolly.
Only engine mod I have is an additional pcv set-up, not dissimilar to an oil catch can with a vent.

 

I appreciate it. Does your PCV setup add any additional unmetered air?

 

Just curious what you are needing the data for?

 

Can you elaborate on what you've got for this pvc setup any why?

 

Long story short, I'm seeing around 10% LTFT & STFT on the car and am trying to get it back down closer to 0.

 

Sorry man, dog had stomach problems, girlfriend's car popped a code, and I had to deal with a family member rearranging our entire kitchen. that was a bad, bad day... I now have hypertension and a cold.

The PCV device is a negative crankcase pressure valve set-up that uses (don't quote me) a venturi, reed valves, and a tiny air filter stolen off a gas powered rc car. called a "T-REV". I have an ebay knock-off that I've been running for maaybe 5 years. link to vivid racing
I'll pull some date for you, then see if I can get around to setting it back to stock. pull numbers again. aside from what they mention (and disregarding their remarks about its having a precision tune in any way,) it also does a very good job keeping oil/blow-by gas out of my throttle body. i like it quite a bit, but can't perfectly explain it . link to where i got mine
design isnt far off from this google image result of a venturi

Import tuner led me to j's racing, which led me to the thingamajig.

Edit: I'm not experienced with fuel trims, but I can pull 'em for dang sure.

EDIT EDIT: i'll be doing a long drive tomorrow. I'll be sure to get'cha numbers.

 

From what I understand +/-10% is normal.

Clicky clicky

 

A properly operating engine will usually see +-3% or so, and I wouldn't even touch it if it was under 5%. I might expect to see a slight positive bias with the amount of ethanol we have in fuel these days, but a consistent +10% on both LTFT & STFT is excessive.

 

Are you stating for a constant speed no change in elevation, or overall driving?

 

There's not much in the way of elevation changes where I live. There's some variation in the fuel trims, which is normal, but the overall average is around +10% for both

 

@jonshonda Thanks!! I'll definitely read up!

@Hysteria I got plenty of screen caps for yuh. Hows this for data? *** captions are BELOW their pictures ***

Hot idle

Hot idle

Hot idle

5th gear 55 mph

4th gear 55 mph


Warming up idle

4th gear 55 mph

5th gear 55 mph

Air temp and location for elevation ref

Humidity

Click the last weather pic if it doesnt show humidity - it's there. Also, whatever these numbers may mean (still need to read), my fit runs pretty effin sweet.

Can still work on deleting the pcv set-up if desired, but thatll take a lil bit

 

Holy cow, thank you. I appreciate the data points. For what it's worth, your fuel trims are pretty high as well. From what I've seen, when you hit 25% you'll probably start throwing a code.

I installed a set of "genuine flow balanced" injectors in the car today, which immediately threw the fuel trim in the opposite direction and eventually pegged the STFT and triggered a rich code (P0172). Pulled them out and now I'm back on the original injectors. I am driving the car 1,000mi out of state on Friday so I'm done playing around with it until I get back.

 

I'm just happy to help. I like this stuff, and staying involved serves to keep my head in the game besides being educational. I'm really interested in the significance of balanced injectors, so if you feel like sharing more of your project you've definitely got a subscriber (and I won't sh*t on your mod choices)


You can see in my first image (if I'm understanding correctly and referring to the right thing) that STFT peaked at 46.9 ~ might have clutch correlation though.


I can't explain, but I can state with certainty that my car runs quite well and has only thrown two codes since I got it back in ~2015-16. I can list my maintenance items if you'd like - none of 'em have been fuel or ignition related besides plugs, valves, and spitting techron through energized injectors. the third of which, only once or twice

If you'd like I can make what will likely be a medium-bad youtube vid so you can hear it do its thing.

Enjoy your trip and stay safe out there!
By the time yer back I should know more about trims.

 

I had purchased "flow balanced" injectors for thia car because I didn't want to invest in new OEM injectors but wanted them to be tested and verified at the proper flow rates to rule them out as a variable. If your car isn't hitting the limits of the fuel trims I wouldn't expect it to run poorly (at least not for fuel delivery reasons). High fuel trims are more of an early indicator of an issue and not something that people normally check.

This is my wife's car so it's totally stock, not much of a project. I do have a '01 MR2 that I am putting a K20A2 into, but I'm not doing a build thread for it. Should be a fun car this summer with the stock A2, and then next winter I'll be building & boosting it with a GTX3071R I have sitting on the shelf.

 

For fun I looked at the LTFT on my 07 Lexus GX470 w/ 221k miles. 3.2% on bank one, and 4.1% on bank two. Not bad lexus....not bad. Honda time to take notes.