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Old 04-24-2008, 08:19 PM   #162 (permalink)
TurboBob
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Join Date: Jan 2003
Location: Near Detroit
Drives: 86 GN 91 RT/TT
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Default Re: MAFT Gen 2 - Anyone?

Quote:
Originally Posted by Drweldin View Post
Couple of observations / questions:
1) I cannot seem to effectively lean the idle. I am going to reset base idle and look at IAC values later....
2) When leaning idle, how long can it take to change AFR? Is it usually instanteous? or should I be waiting a couple of minutes?
3) I can get lo-load page to give me stoich readings at each rpm level with the car warm, and stationary,me just applying and holding trhottle and adjusting....going up thru the rpm range....but, I have to add + 20% or so at 1200 and above-- is this "normal"? second,is this a proper way to tune lo-load?? So I effectively net -17% or so user tune (560 injectors)....but keep in mind, ported heads, free flowing exhaust bigger turbos, etc....so maybe its ok (?) It does sound and feel better with the extra fuel....I have not driven it yet. Im a little worried about the transition from -37 at 800 rpm to -17 at 1200 ....not sure if that will present any issues....
Any good links to tuning?

EDIT: #1 IAC Seems good, and seems to act normal. NEvermind on #3, experimanted and found this is not a good way to tune. While it works with no load, I was indeed rich at cruise afterwards, although a little more fuel in the lower range of the lo load page (rpms) does seem to smooth the car out a tad...
#2 when I make a change to idle, I rev the car a couple times and let it settle back in.....

I have been tuning all my part throttle stuff using the O2 trim. I tune the car a little rich so the trims all go to 81, then I tune for an O2 trim of 80 or so. This way I can see if the ECU is in open loop (stuck O2 trim) or not.... Works pretty well.

Bob
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1991 Stealth RT/TT, Grooms Shortblock, 13G's.

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