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Thread: Target AFR, Fuel Modifiers, Learning - Precedence?

  1. #1

    Default Target AFR, Fuel Modifiers, Learning - Precedence?

    I need to tune the fuel modifiers for Air & Coolant Temp Enrichment, but I could use a little direction. How does Target A/F Ratio & Learning play into those modifiers? I.E. Do the modifiers enrich over & above the Target A/F Ratio? Also, can the modifiers be changed while the ECU is still Learning? Thanks for any input.

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
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    Quote Originally Posted by xyzrbs View Post
    How does Target A/F Ratio & Learning play into those modifiers?
    I can get into this in more detail if necessary, but see if this thread answers some questions:
    http://forums.holley.com/showthread....el-Learn-Table (Closed Loop & Learn Tables)

    I.E. Do the modifiers enrich over & above the Target A/F Ratio?
    Yes. During the Coolant Temperature Enrichment period, the A/F Ratio Offset Table enriches the Target A/F Ratio Table.
    Closed Loop is active during Coolant Temperature Enrichment, but Learning is not (until normal operating temperature).

    EFI Software Help Information/Instructions:
    - On the top Toolbar, click "Help" & "Contents". This opens all Help topics.
    - When navigating the software, click "Help ?", drag it to any parameter and click again.
    ..This automatically opens the definitions for that specific parameter.
    - Tuning information can be read by clicking the F1 key, when you're viewing any screen.
    http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual)

    Also, can the modifiers be changed while the ECU is still Learning?
    Yes.

    Originally Posted by Danny Cabral
    Learn Issues (Self-Tuning)
    Check the Closed Loop & Learn settings in System Parameters.
    Ensure both are Enabled and "Learn Gain" is 100%.
    Learning won't happen if the idle (RPM) is unstable.
    Try blocking off the IAC passage to see if it stabilizes the idle. If so, it may be IAC related.
    Ensure the Closed Loop & Learned Compensation Limits haven't reached their percentage limits.
    Initially, if the Closed Loop Advanced Control (1-5) is set too high, it can sometimes inhibit Learning.
    Also, ensure the Learning isn't working because of repeated "RPM Errors", causing repeated ECU "syncing".

    Learning happens at all RPM, provided the Learn Parameters are programmed as such.
    Is the Coolant Temperature Enrichment % or A/F Ratio Offset still active? These must be at 100% & zero to enter Learn mode.
    You may need to reconfigure these tables if you're running the engine colder than what the base calibration specifies.

    Closed Loop & Learning isn't active during periods of acceleration enrichment or deceleration (zero TPS, 400 RPM above target idle).
    The engine needs to be at "steady-state" RPM for the Learning to function, at lower RPM.
    The Closed Loop Status has many momentary periods when it's inactive (Open Loop mode).
    This is normal due to the TPS & MAP based acceleration enrichment (transient fueling).
    Also, any "noise" on the TPS or MAP signal wire (false Rate of Change) will deactivate Closed Loop.
    http://documents.holley.com/techlibr...__statuses.pdf (Sensor Diagnostics & Statuses)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  3. #3

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    Quote Originally Posted by Danny Cabral View Post
    Yes. During the Coolant Temperature Enrichment period, the A/F Ratio Offset Table enriches the Target A/F Ratio Table.
    Closed Loop is active during Coolant Temperature Enrichment, but Learning is not (until normal operating temperature).
    Great input! Can you further clarify: How do the Coolant Temperature Enrichment and A/F Ratio Offset Tables interact? Thanks again.

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
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    22,981

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    Quote Originally Posted by xyzrbs View Post
    Great input! Can you further clarify: How do the Coolant Temperature Enrichment and A/F Ratio Offset Tables interact? Thanks again.
    These two cold engine (coolant temperature) tables work in conjunction with each other.

    The Coolant Temperature Enrichment Table modifies (enriches) the Base Fuel Table.
    Tuning this table will minimize the amount of cold engine Closed Loop compensation.

    The A/F Ratio Offset Table modifies (enriches) the Target Air/Fuel Ratio Table.
    Tuning this table allows a cold engine to run smooth without running too rich or too lean.

    It's also important to consider how rich the Target A/F Ratio table is (especially at idle), before adjusting
    this table. For example, some applications need a slightly rich Target A/F Ratio table at idle; so since it's
    already rich, not much cold A/F Ratio Offset enrichment is required. On the other hand, if the Target A/F
    Ratio table at idle is lean, then it may require more cold A/F Ratio Offset enrichment. Don't enrich the A/F
    Ratio Offset table more than necessary, and it's usually rich enough (or too rich) in the base calibrations.

    EFI Software Help Information/Instructions:
    - On the top Toolbar, click "Help" & "Contents". This opens all Help topics.
    - When navigating the software, click "Help ?", drag it to any parameter and click again.
    ..This automatically opens the definitions for that specific parameter.
    - Tuning information can be read by clicking the F1 key, when you're viewing any screen.
    http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

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