im confused vol. 1
#1
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From: springfield il
im confused vol. 1
Dr. jay as soon as i can get around to scanning my car which will likely be saturday if i dont get anxious about it and do it sooner ill start this thread. IN the mean time i have a few questions:
An afc just changes the maf freaquency right? so wouldnt the fuel system respond to that and richen or lean out the af mixture accordingly, or would the it try to change the ammount of air coming into the motor to accomadate for the ammount of fuel your trying to add or take away?
An afc just changes the maf freaquency right? so wouldnt the fuel system respond to that and richen or lean out the af mixture accordingly, or would the it try to change the ammount of air coming into the motor to accomadate for the ammount of fuel your trying to add or take away?
#2
It changes the maf frequency and load variables so your transmission will shift a little different (not at WOT) but anyways
It just richens or leans the mixture and depending on your setting, the computer may compensate for it beign too rich or too lean.
It just richens or leans the mixture and depending on your setting, the computer may compensate for it beign too rich or too lean.
#3
Thread Starter
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Joined: Sep 2003
Posts: 1,369
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From: springfield il
Ok finally got around to scanning my car today and here is what i found. First off i think it is important to point out that im not running a 2.2 inch pulley, its around 2.5 inch. What i did is start the car and let it warm up, then scanned it. here is part of what i found.
AFC was tuned at 92 percent and the car was turned off
LTFT=127
LTFTCL=1
STFT=112
Closed loop status
Spark adv.=18
AFR=0
i then turned the car back on and got this
AFC tuned at 92 percent
LTFT: 135
LTFTCL:1
STFT:128
Open loop status
Spark adv.:19
AFR:0
What does this tell me and is there anything else i should include that would give me more info?
AFC was tuned at 92 percent and the car was turned off
LTFT=127
LTFTCL=1
STFT=112
Closed loop status
Spark adv.=18
AFR=0
i then turned the car back on and got this
AFC tuned at 92 percent
LTFT: 135
LTFTCL:1
STFT:128
Open loop status
Spark adv.:19
AFR:0
What does this tell me and is there anything else i should include that would give me more info?
#4
Originally Posted by jachin
Ok finally got around to scanning my car today and here is what i found. First off i think it is important to point out that im not running a 2.2 inch pulley, its around 2.5 inch. What i did is start the car and let it warm up, then scanned it. here is part of what i found.
AFC was tuned at 92 percent and the car was turned off
LTFT=127
LTFTCL=1
STFT=112
Closed loop status
Spark adv.=18
AFR=0
i then turned the car back on and got this
AFC tuned at 92 percent
LTFT: 135
LTFTCL:1
STFT:128
Open loop status
Spark adv.:19
AFR:0
What does this tell me and is there anything else i should include that would give me more info?
AFC was tuned at 92 percent and the car was turned off
LTFT=127
LTFTCL=1
STFT=112
Closed loop status
Spark adv.=18
AFR=0
i then turned the car back on and got this
AFC tuned at 92 percent
LTFT: 135
LTFTCL:1
STFT:128
Open loop status
Spark adv.:19
AFR:0
What does this tell me and is there anything else i should include that would give me more info?
FYI - Middle ground on ST trims are 128. The higher the number the more lean you are, the lower the number the richer you are. Think of this as the pulse width the computer is telling the injectors to fire at. Higher = Pulse longer because any lower and there isn't enough fuel. Make sense?
o2mV would also be helpful, cruising and idle.
#5
Originally Posted by 95naSTA
It changes the maf frequency and load variables so your transmission will shift a little different (not at WOT) but anyways
It just richens or leans the mixture and depending on your setting, the computer may compensate for it beign too rich or too lean.
It just richens or leans the mixture and depending on your setting, the computer may compensate for it beign too rich or too lean.
#6
Originally Posted by DrJay
Originally Posted by 95naSTA
It changes the maf frequency and load variables so your transmission will shift a little different (not at WOT) but anyways
It just richens or leans the mixture and depending on your setting, the computer may compensate for it beign too rich or too lean.
It just richens or leans the mixture and depending on your setting, the computer may compensate for it beign too rich or too lean.
When i stray too far off from 100% my partial throttle shifts change.
Also with the 4t65'* the maf signal is a variable for determining line pressure.
#8
Originally Posted by DrJay
Ok finally got around to scanning my car today and here
FYI - Middle ground on ST trims are 128. The higher the number the more lean you are, the lower the number the richer you are. Think of this as the pulse width the computer is telling the injectors to fire at. Higher = Pulse longer because any lower and there isn't enough fuel. Make sense?
FYI - Middle ground on ST trims are 128. The higher the number the more lean you are, the lower the number the richer you are. Think of this as the pulse width the computer is telling the injectors to fire at. Higher = Pulse longer because any lower and there isn't enough fuel. Make sense?
#10
Thread Starter
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Joined: Sep 2003
Posts: 1,369
Likes: 1
From: springfield il
So for the most part, everything checks out. IM going to see about leaning the afc out a little bit next weekend, i dont really have the gas or money to do this right now. Out of curiosity how high and how low will the fuel trims go? I also want to start messing with the afc in advanced mode but im not really sure how to tune it, the fuel curve should be a gradual slope right THen the only difference between stock and aftermarket injectors is that basically the holes are bigger, and i need to use the afc because if they were to fire at the same rate as the stock injectors, it would deliver more fuel than what it needs right? When im tuning the afc, im tuning it to 92 percent of which maf peramiter?