The fuel pressure regulator adjustment begins...
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From: St. Louis
The fuel pressure regulator adjustment begins...
<center><img src="http://pictureposter.audiworld.com/113022/fueling.jpg"></center><p>
I am trying to take a baseline before I start adjusting fuel pressure. I logged blocks 031 and 032 (graph above is of 32) over block 002. Can anyone help me interpret the graph above?
I am trying to take a baseline before I start adjusting fuel pressure. I logged blocks 031 and 032 (graph above is of 32) over block 002. Can anyone help me interpret the graph above?
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There's no point in really logging LTFT's....>>
As the number self corrects all the time in small increments. It usually stabilizes after normal driving (no WOT) and can be read just sitting in the driveway with the key on...That said, the Negative numbers indicate a slight rich correction. (that doesn't necessarily mean it's running rich though.) It's a correction. When you go WOT though the Preset fuel maps are added to the Negative correction so that's where the rich shows up as those mixtures are no longer controlled by the 02's. RPM logging should be done measuring the 02 voltages (I forget the block). Multiply them times 14.7 for an approximated Air Fuel ratio..
Get the correction as close to "0" as you can, erring on the rich side (so less Fuel pressure in this case). Keep the A/F in the 12:1 range for max power..
<img src="http://images29.fotki.com/v290/photos/7/7305/776256/fueltrim-vi.jpg">
Get the correction as close to "0" as you can, erring on the rich side (so less Fuel pressure in this case). Keep the A/F in the 12:1 range for max power..
<img src="http://images29.fotki.com/v290/photos/7/7305/776256/fueltrim-vi.jpg">
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That's pretty flakey..>>
and really doesn't tell me anything! Forget measuring 02 #2. there is another block that just does #1 with a few other things that'll give you a smoother output like this:
<img src="http://images107.fotki.com/v542/photos/7/7305/130918/MAF_af-vi.jpg">
<img src="http://images107.fotki.com/v542/photos/7/7305/130918/MAF_af-vi.jpg">
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AudiWorld Senior Member
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From: St. Louis
off topic, but grabbed boost while I was at it
<center><img src="http://pictureposter.audiworld.com/113022/boost.jpg"></center><p>I have a boost machine in parallel with the n75. Looks like I am overboosting once the turbo kicks in. Maybe that is causing the low point in the a/f graph in the post above...
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Not an overboost....>>
Actual IC pressure is usually over command. Almost looks like you have the BM set below the threshold where it is operational. 2200 milibars minus atmospheric = 1.200 bar x14.5 (PSI conversion) = 17.4 PSI. Probably your normal Chipped Boost.
On the onset, Zero it out (turn fully COUNTERCLOCKWISE), then start turning clockwise until you just start to feel it snug up a little. This is usually at 1.5-1.75 turns, On the regulator, determine how many turns you are at by turning CLOCKWISE to the stops, re-set to where it was and add another turn counterclockwise....Continue advancing the regulator until you get a nice 22psi peak in a high torque 3rd gear throttle application..
Always measure in 3rd gear.
A good suite of diagnostic blocs are:
002 (Mass air)
118 (intake temp, N75 duty, IC pressure)
204 (Command, IC, and Manifold pressures)
3rd gear start at 2K, then go WOT to redline..
On the onset, Zero it out (turn fully COUNTERCLOCKWISE), then start turning clockwise until you just start to feel it snug up a little. This is usually at 1.5-1.75 turns, On the regulator, determine how many turns you are at by turning CLOCKWISE to the stops, re-set to where it was and add another turn counterclockwise....Continue advancing the regulator until you get a nice 22psi peak in a high torque 3rd gear throttle application..
Always measure in 3rd gear.
A good suite of diagnostic blocs are:
002 (Mass air)
118 (intake temp, N75 duty, IC pressure)
204 (Command, IC, and Manifold pressures)
3rd gear start at 2K, then go WOT to redline..