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Old 04-27-2020, 12:51 AM   #49
Irace86.2.0
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Quote:
Originally Posted by Ultramaroon View Post
I'm no expert but I got curious. Looking at the beginning of one of your logs before the engine is started, MAP and atmospheric pressure should match. (I think. Right?) If that's the case, your MAP is reading 0.12 bar low. I think that's enough of an offset to drive the AFR lean.
I don't think that is a problem. He is at 5000 ft which is why he is at 0.88 bar. I would need a tuner's opinion, but I don't believe the atmospheric pressure is measured; they probably add an arbitrary valuee in there. US cars use MAP; we don't have a separate atmospheric pressure sensor. If they were the same value then they would also both change to vacuum and boost, but they never do. Atmosphere is always fixed. Maybe they include it so someone could get a rough number of relative pressures as a calculation difference against atmospheric pressure. I don't know.

I don't entirely understand this statement. Maybe a tuner knows. Maybe the CARB tune is entirely MAF based. I don't know.

Quote:
On USA region ROMs when using the CPC pressure sensor as an input into the ECU the atmospheric pressure reading will be incorrect (as the ECU uses the CPC Pressure sensor for the atmospheric pressure reading).

By enabling the check box, the atmospheric pressure will be calculated from the MAP sensor and will read correctly.
https://www.ecutek.com/Products/Trad...tures#brz-atmo
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