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-   -   question about maf sensors (http://www.the370z.com/engine-drivetrain/122400-question-about-maf-sensors.html)

Z_ealot 07-13-2017 12:22 AM

just an update....after I changed out my pcv valves I now see my fuel trims in opposite positions at startup. before changing out the pcv valves on startup my LTFT would be at -10.94% with STFT trending towards +9%. once warm with the old pcv valves my LTFT would stay stuck at -10.94% with STFT at around +3% or close to 0%, when I would snap the throttle open LTFT would stay pinned at -10.94%. now with new PCV valves on startup my LTFT is now at +9% and STFT is at a -10% until warm up when LTFT seems to settle at around -8% and STFT seems to settle around 0%, interesting to note however is now when I snap the throttle open all fuel trims line up at 0% or close to it and go back to the previous figures when let back down to idle. not to jump to any conclusions, but to me at least the old PCV valves seem to have been the culprit when it came to the fuel trims seeing as everything is now lining up with the new PCV valves.

Ommateal 07-14-2017 03:25 PM

Quote:

Originally Posted by Z_ealot (Post 3674130)
just an update....after I changed out my pcv valves I now see my fuel trims in opposite positions at startup. before changing out the pcv valves on startup my LTFT would be at -10.94% with STFT trending towards +9%. once warm with the old pcv valves my LTFT would stay stuck at -10.94% with STFT at around +3% or close to 0%, when I would snap the throttle open LTFT would stay pinned at -10.94%. now with new PCV valves on startup my LTFT is now at +9% and STFT is at a -10% until warm up when LTFT seems to settle at around -8% and STFT seems to settle around 0%, interesting to note however is now when I snap the throttle open all fuel trims line up at 0% or close to it and go back to the previous figures when let back down to idle. not to jump to any conclusions, but to me at least the old PCV valves seem to have been the culprit when it came to the fuel trims seeing as everything is now lining up with the new PCV valves.

That's great to hear, keep us updated to make sure this is a long term fix for your issue... Not sure if it will help me but I might change mine just because i'm paranoid that ANY part could be the problem for me at this point... sigh. I wouldn't be surprised if they blamed my issues on a slightly loose fender bolt.

Z_ealot 07-14-2017 04:14 PM

Quote:

Originally Posted by Ommateal (Post 3674721)
That's great to hear, keep us updated to make sure this is a long term fix for your issue... Not sure if it will help me but I might change mine just because i'm paranoid that ANY part could be the problem for me at this point... sigh. I wouldn't be surprised if they blamed my issues on a slightly loose fender bolt.

Drove her today and fuel trims are still getting better, down to about -7% on long terms with short terms staying near 0 at idle. Still have to torque down the pcv valves to the correct torque, but with just tightening them by hand as much as i could without overdoing it the car is now stable and the stumbling at idle is gone as well as the slight misfire and hesitation i was getting.


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