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Thread: Off Idle Hesitation

  1. #21
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    Quote Originally Posted by Danny Cabral View Post
    The Closed Loop Compensation % factor is found in the Data Monitor & Datalogger; it's the "CL Comp" channel. That's the amount to adjust.
    Perfect, thanks!

  2. #22
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    Quote Originally Posted by 66FSTBK View Post
    Perfect, thanks!
    But you can't quickly rev the engine to full throttle and expect to tune off it.
    You need brief sustained WOT runs, at various RPM points to datalog & tune.
    This is why tuning on a dyno is preferred. It's a safe, controlled environment.
    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. #23
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    Quote Originally Posted by Danny Cabral View Post
    But you can't quickly rev the engine to full throttle and expect to tune off it.
    You need brief sustained WOT runs, at various RPM points to datalog & tune.
    This is why tuning on a dyno is preferred. It's a safe, controlled environment.
    So you are saying that it's not a good idea to make these changes that you suggested without dyno tuning? I have watched my AFR gauge while driving, WOT & cruising, and it has been very consistent with no real lean or rich points. I'm not expecting to tune the entire system this way, just this area. I'm happy with the way it runs & performs in all areas (still tinkering with hard starts).

  4. #24
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    Quote Originally Posted by 66FSTBK View Post
    So you are saying that it's not a good idea to make these changes that you suggested without dyno tuning?
    No, that's not what I'm implying. I'm just saying there's a specific way to drive, in order to make use of a good datalog. Some people are not comfortable with breaking the speed limit law (Link), so a dyno becomes necessary.
    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.

  5. #25
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    Quote Originally Posted by Danny Cabral View Post
    No, that's not what I'm implying. I'm just saying there's a specific way to drive, in order to make use of a good datalog. Some people are not comfortable with breaking the speed limit law (Link), so a dyno becomes necessary.
    You're just saying that an overall tune for the system is best accomplished on a dyno. I'll see how this turns out. If it works, and I can get my hot starts figured out, then it will be perfect for me.

    Regarding the hot starts, the car cranks smoothly and fires up quick when the thermostat is 160° and below. Anything above that is very inconsistent. Sometimes it will start quickly, other times it will sound like it struggling and will crank excessively.

    -I have varied the crank timing from 10°-17° and it seems to like under 15° somewhere but not a real noticeable change on hot starts, I can just tell a difference when the engine has set overnight or when it drops below 160°.

    -I adjusted the Startup Enrichment in the area of 160°-260°. Currently at 23 lb/hr. I did try your method of depressing the pedal during cranking and it seemed to help it start.

    Quote Originally Posted by Danny Cabral View Post
    • Notes - starts & runs, but potentially could be better:
    If it starts worse, with the throttle cracked open, it's too lean.
    If it starts better, with the throttle cracked open, it's too rich (or throttle blades were closed too far.)
    This would mean it was too rich. I have not had time to drop these values down and test yet.

    -If leaning the Startup Enrichment doesn't work then I will adjust the IAC Parked Position upward by about 4-5% around the aforementioned temperature range. The manual said a number too low here could create hard starts.

    -I'm running a MSD 6A box and Motorcraft TFI module as well.

    Quote Originally Posted by Danny Cabral View Post
    The Closed Loop Compensation % factor is found in the Datalog; it's the "CL Comp" channel. That's the amount to adjust.
    During the rich spikes, there was a 0% CL compensation. During the lean spike there was as much as a 14% CL compensation. Do I just leave the rich area alone and address the lean one?
    Last edited by 66FSTBK; 12-23-2014 at 10:58 AM.

  6. #26
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    Quote Originally Posted by 66FSTBK View Post
    Regarding the hot starts, the car cranks smoothly and fires up quick when the thermostat is 160° and below. Anything above that is very inconsistent.
    I can't offer any further startup tuning advice, than what you'll read here:
    http://forums.holley.com/showthread....6254#post36254 (Startup Tuning Thread)

    During the rich spikes, there was a 0% CL compensation. During the lean spike there was as much as a 14% CL compensation. Do I just leave the rich area alone and address the lean one?
    Again, it depends how that AFR spike data was recorded. Was this a quick stab on the throttle? If so, read the 3rd paragraph below. If not, tune as you stated above. In other words, it may have been 0% CL Compensation due to an Acceleration Enrichment period, which deactivates Closed Loop & Learn.

    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) isn't stable.
    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 RPMs, 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.

  7. #27
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    I'll keep performing trial & error on the starting.

    The quick stab of the throttle was when I had that blip or hesitation. Decreasing the AE helped with that.
    The AFR spikes are occurring with a smooth, light acceleration as seen in the video.

    Here's the Fuel Table after I merged Learning and base, smoothed it, then manually smoothed it in increments as you suggested.



    Here's the zoomed in portion of the lean spike overlay that I enriched.
    I manually smoothed it after adding fuel per the CL Compensation %.
    You can see the fuel increase on the graph. I also disabled "Base Fuel Learn Enabled."

    Last edited by 66FSTBK; 12-23-2014 at 12:14 PM.

  8. #28
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    I was able test it out today.

    First, I loaded my old GF, zeroed out the AE graph, and then tried to recreate the lean & rich spike. Still there. I was told that this might indicate an all around rich fuel table.

    Second, I loaded the new GF that I modified the lean spike and manually smoothed out (pictures on previous post). I did not mess with the rich spikes. Found that this change did this: http://youtu.be/TdMNcVFVKQo

    Third, out of curiosity, I leaned out the entire Fuel Table by 4%. Aside from the crack of the throttle and the rich spike, the AFRs were really spot on when I viewed the AFR gauge. I did not log my test though.

    Fourth, I messed with the Startup Enrichment, IAC Parked and Cranking Timing. Really kept the Startup Enrichment the same, but bumped up the IAC Parked Position. Seemed to make a big difference.

  9. #29
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    Quote Originally Posted by 66FSTBK View Post
    Still there. I was told that this might indicate an all around rich fuel table.
    Yes, this is what I was referring to in post #6. But yours may only be rich in the WOT region of the Fuel Table.

    Second, I loaded the new GF that I modified the lean spike and manually smoothed out (pictures on previous post). I did not mess with the rich spikes. Found that this change did this: http://youtu.be/TdMNcVFVKQo
    When snapping the throttle blades shut, the WBO2 sensor will read rich; but not because fuel was added,
    because you've abruptly cut airflow off to the engine. After all, it is an oxygen sensor, not a fuel sensor.
    However, the deceleration area of the Base Fuel Table can be tuned (leaned) to alleviate this condition.

    Third, out of curiosity, I leaned out the entire Fuel Table by 4%. Aside from the crack of the throttle and the rich spike, the AFRs were really spot on when I viewed the AFR gauge. I did not log my test though.
    This is a step in the right direction. Now instead of modifying the entire Fuel Table, modify only the areas that need
    it (left click & drag to highlight selected area, and right click for Offset Selected), and blend it in on the Fuel Graph.

    Fourth, I messed with the Startup Enrichment, IAC Parked and Cranking Timing. Really kept the Startup Enrichment the same, but bumped up the IAC Parked Position. Seemed to make a big difference.
    Yes, the Cranking Fuel & the IAC Parked Position have the greatest effect on startup.
    The Cranking Fuel & IAC Parked Position are the "cranking air/fuel ratio".
    The new "Fuel Prime" feature works well to quickly "fire" (start) the engine.
    This is especially true when the engine has been stone cold & dry for days.
    However, I'd temporarily disable it, and tune that starting parameter last.
    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.

  10. #30
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    Quote Originally Posted by Danny Cabral View Post
    When snapping the throttle blades shut, the WBO2 sensor will read rich; but not because fuel was added,
    because you've abruptly cut airflow off to the engine. After all, it is an oxygen sensor, not a fuel sensor.
    However, the deceleration area of the Base Fuel Table can be tuned (leaned) to alleviate this condition.
    Do you think I did OK with tuning the lean area then, as I did not see the lean spikes any longer? I guess I shouldn't tune these rich areas in the same manner I did the lean spike since there was no +/- CL Compensation on the log...because it was airflow being abruptly cutoff to the engine. These rich readings like this appeared when I would let off the gas and clutch, so same situation I guess...air cut off.

    Quote Originally Posted by Danny Cabral View Post
    This is a step in the right direction. Now instead of modifying the entire Fuel Table, modify only the areas that need
    it (left click & drag to highlight selected area, and right click for Offset Selected), and blend it in on the Fuel Graph.
    Do I just pull the log up and pay attention to the rich areas and tune accordingly then? I tested yesterday with the CL Learn disabled as you suggested, and the car seemed more consistent and ran really well. I think from here on out, I will leave that disabled since my tune is so close.

    Quote Originally Posted by Danny Cabral View Post
    Yes, the Cranking Fuel & the IAC Parked Position have the greatest effect on startup.
    The Cranking Fuel & IAC Parked Position are the "cranking air/fuel ratio".
    The new "Fuel Prime" feature works well to quickly "fire" (start) the engine.
    This is especially true when the engine has been stone cold & dry for days.
    However, I'd temporarily disable it, and tune that starting parameter last.
    I will disable that for tuning purposes. Thanks for the suggestion.
    This is what I arrived at. Each temp range seemed to like a little different IAC Parked Position. Still going to tinker with this part.




    I did run a log during slow acceleration, shift, acceleration. Before the -4% fuel though.

    Last edited by 66FSTBK; 12-24-2014 at 10:23 AM.

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