My MAFless tune/log results
03-31-2005, 09:43 AM
#1
My MAFless tune/log results well i took my maf sensro out of the car and decided to just run SD all the time. last time i went out to log it was in the 20's, last night it was 50-60 out and the fuel trims each time were all the same -2 to 0. so that is about a 30 or 40 degree swing in temperatures and the car seemed to run no different.
any of you all seeing the same thing? i am hearing people having 4 or 5 point swings in their trims from day to day, wonder why?
any of you all seeing the same thing? i am hearing people having 4 or 5 point swings in their trims from day to day, wonder why?
03-31-2005, 10:06 AM
#3
temp and humidity play the largest roles. plus the pressure wasnt the same anyway, one was on a day with high pressure, real nice out and the other was done with low pressure and a storm moving in. the real test i think will be a 90 deg day with high humidity.
03-31-2005, 01:53 PM
#4
I tuned in 60* weather, last week I disconnected the maf in 30* weather and it was running -8 ltft. Did you make corrections in the IAT vs a/f correction table? I think if you set a basepoint of say 60 degrees you could make IAT a/f corrections that would keep your afr inline in hot or cold temps. I've yet to experiment with it though.
04-01-2005, 11:01 AM
#6
Launching!
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I'm also interested in this subject as I have just recently decided that I'm tired of trying to dial in the MAF. Its just getting to be more effort than its worth at this point. I wonder how a Stock PCM deals with wether changes of humidity and presure and temp? Just by adjusting the LTFT & STFT? So that 90% of the year a stock car is going to be having to make major adjustments to the LTFT to keep AFR correct?
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04-01-2005, 11:33 AM
#8
the maf sensor has error in it too, not as bad as no maf from what i have seen but if you tune in a neutral temp and humidity it will be ok. i havent done the calculations to find the right temp but all i know is with the maf hooked up it didnt do **** really helping the fuel trims, they still changed from hot to cold by about 5 points or so. so far in SD i havent seen that high of a swing, the parts that are tuned good are +/-1 or so
04-01-2005, 08:00 PM
#9
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I'm running in SD too right now. I tuned on the one REALLY cold day here in Florida (about 50*). I was about -1 to -3% then. I haven't hooked up the scanner with this warmer high 80* weather, but I can tell it's lackin some responsiveness and power, mainly in low-mid rpms. I'm gonna retune in SD tomorrow and then try to tune the MAF tables for the first time tomorrow, so I'll see how far off 40* threw off my tune.
Ryan
Ryan
04-01-2005, 08:45 PM
#10
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Originally Posted by SmokingWS6
I tuned in 60* weather, last week I disconnected the maf in 30* weather and it was running -8 ltft. Did you make corrections in the IAT vs a/f correction table? I think if you set a basepoint of say 60 degrees you could make IAT a/f corrections that would keep your afr inline in hot or cold temps. I've yet to experiment with it though.
