AFR variations due to temperature?
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AFR variations due to temperature?
today, while logging my AFR on a 4th gear pul, my AFR has gone 0.5 richer compared to 2 weeks ago whe the temperature was much cooler/colder...does temperature have such a drastic effect on AFR?
more about the car:
-stock evo ix with 1000cc/min methanol injection
-27psig peak tapering to 21psig at redline
-flow rate of methanol was the same as 2 weeks ago, logged thru a aquamist dds3 failsafe.
more about the car:
-stock evo ix with 1000cc/min methanol injection
-27psig peak tapering to 21psig at redline
-flow rate of methanol was the same as 2 weeks ago, logged thru a aquamist dds3 failsafe.
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Joined: Dec 2006
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Remember, your ECU pretty much guesses at AFR WOT. Closed loop, it should stay very close to 14.7 because it has a narrow band sensor to help it find that point.
But open loop it takes a 'best guess', using such factors like air flow and inlet temp. So, it if you have moded a car to effect VE, you need to adjust the 'guess' tables accordingly.
-jjf
But open loop it takes a 'best guess', using such factors like air flow and inlet temp. So, it if you have moded a car to effect VE, you need to adjust the 'guess' tables accordingly.
-jjf
Thread Starter
Evolved Member
iTrader: (4)
Joined: Sep 2003
Posts: 3,456
Likes: 0
From: Kingdom of Saudi Arabia
Remember, your ECU pretty much guesses at AFR WOT. Closed loop, it should stay very close to 14.7 because it has a narrow band sensor to help it find that point.
But open loop it takes a 'best guess', using such factors like air flow and inlet temp. So, it if you have moded a car to effect VE, you need to adjust the 'guess' tables accordingly.
-jjf
But open loop it takes a 'best guess', using such factors like air flow and inlet temp. So, it if you have moded a car to effect VE, you need to adjust the 'guess' tables accordingly.
-jjf
