15mpg and an 032 measure of +4% and +24%. WTH?
09-05-2008, 06:07 AM
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15mpg and an 032 measure of +4% and +24%. WTH?
Was fine not too long ago... Just replaced the MAF maybe a month ago? Did the primary O2 two months ago. Had 032 close to 0 for idle + @ throttle. All I did in the past two weeks was mount my Evo FMIC. And stuff was fine then... But, then my wideband O2 sensor fouled. Maybe the primary is fried as well, but why? Heat? Argh... Previous tank, I got 17mpg, and the tank before that I got the usual 22.
Any guesses?
Any guesses?
09-05-2008, 07:29 AM
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Agreed... Positive values indicate engine running lean so it overcompensates by running rich
which is why it is going rich (adding fuel as evidenced in second field).
Could also be bad MAF.
However I think it's supposed to run rich to some degree before
becoming Stoichiometric.<ul><li><a href="http://wiki.ross-tech.com/index.php/Fuel_Trim_Info">VAG-COM wiki info I gleaned on fuel trim.</a></li></ul>
Could also be bad MAF.
However I think it's supposed to run rich to some degree before
becoming Stoichiometric.<ul><li><a href="http://wiki.ross-tech.com/index.php/Fuel_Trim_Info">VAG-COM wiki info I gleaned on fuel trim.</a></li></ul>
09-05-2008, 07:57 AM
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Yes, the turbo isn't sealing against the test pipe b/c one of the bolt was torqued off.
But, while I wasn't expecting it to be totally 'fine,' this recent bit is kind of dramatic. I'm not driving the car until I get the rest of the new parts in, but... Jeez.
09-05-2008, 08:01 AM
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Yeah... But, you think my MAF could've gone bad in a month or so?
And it runs rich at start up... And even after, it's supposed to run a little more rich than stoich since it's imperfect combustion and such.
09-05-2008, 08:23 AM
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Correct. It's supposed to run rich <right> at startup...
but then go stoich at some point at idle. Same thing after running
on highway it should eventually go close to stoich... not perfect as
you've noted, but within the 10% range I would think.
I doubt it's the MAF at this point especially if it's new and you're
experiencing an exhaust leak. Fix that first and see.
on highway it should eventually go close to stoich... not perfect as
you've noted, but within the 10% range I would think.
I doubt it's the MAF at this point especially if it's new and you're
experiencing an exhaust leak. Fix that first and see.
09-05-2008, 08:57 AM
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Well, I'm hoping it's nothing fuelling related, b/c that would interfere with my new setup
whenever I finally get it. I'm getting a new FPR, and thinking about a new fuel pump.
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