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Thread: Lean Surge During 2200-3000 RPM Cruise

  1. #1

    Default Lean Surge During 2200-3000 RPM Cruise

    Can't seem to quite figure this out. Been an issue since fire on the Terminator X. Figuring it's some sort of cam surge, but cannot quiet nail it. I have a huge spike in my Learn Table. Around 40% every time I check the learn.
    2004 5.3L
    Summit Stage 2 Turbo Cam
    True Bosch 210s using FIC2150 data, also tried 2000cc ID data which is very similar.
    Victor jr intake (I drilled a hole at the top of the elbow and solid mounted the GM 2.5 bar MAP there.)
    Single turbo on the Hooker turbo setup.
    Wideband around 12" post turbo.
    6 speed, 3.50 gears, 26" tire.

    At first I assumed it was due to deceleration being super lean, but it seems to follow if I'm cruising at 32-39 kPa it will surge from 14 AFR to 17 AFR. Tried timing in the areas of 26°, 30°, 32° etc. All the same results. Tried shutting off learning in those cells, same results. Other than these issues it runs amazing, minus the super lean decel making it very raspy. I have reset the IAC, reads around 4% hot idle. Looked through the datalogs, don't seem to see misfires or any sensor related issues, just AFR surging. They only thing it seems to follow is due to having a 1:1 regular it happens when my fuel pressure is at around 34 psi. (Base is tuned and set to 43 psi.) Next ideas I'm thinking is remove and plug the vacuum line on the regulator, and possibly try running Open Loop only. Jay

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    Last edited by jay_rich; 06-07-2019 at 09:44 PM.

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,709

    Default

    If you know it's a lean surge at a certain RPM, then maybe the engine doesn't like the Target A/F Ratio table in that area. Also, pay attention to the paragraph in blue print below:

    Originally Posted by Danny Cabral
    Quick Datalogger Information:
    Always provide data, not just symptoms. Is the AFR & ignition timing optimized? Overlay the datalog onto your Global File.
    Ensure the Target A/F Ratio table is properly programmed for your engine. Ensure the ECU is "Learning" (Learn Table LINK).
    Scroll through the datalog to the problem area. Then look exactly where this happens on the Base Fuel & Timing Tables. Scrutinize:
    RPM, MAP, MAT, TPS, CTS, IAC, Target AFR, AFR Left, CL Comp, Ignition Timing, Duty Cycle, Fuel Flow, Fuel Pressure & Battery.

    Using the Holley EFI software (LINK), look at where the live cursor moves to during this occurrence, and
    manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing).


    I find the most helpful datalog function, is overlaying the datalog on your Global File.
    I'm in the habit of using the datalog Overlay feature every time I review a datalog.
    Click on "Datalog" (on the top Toolbar), "Activate Overlay", then "Open Data Log".
    You can literally "playback" a recorded event, and watch it as it happened on any screen.
    Minimize (shrink) the datalog window, and move it to the bottom of any Global File screen.
    Then click & scroll anywhere on the datalog, and watch it playback on your Global File (EFI software).
    http://documents.holley.com/techlibr...9r10543rev.pdf (Holley EFI Datalogger Instructions)
    https://forums.holley.com/showthread...s-amp-Datalogs (Datalog & System Log Information - Read "NOTES")
    https://www.youtube.com/watch?v=iqHO...C6FEA0BB99AF17 (How To Record & Email A Datalog)
    https://www.youtube.com/watch?v=q7OZUXLRS1Q (How To Record A System Log & Diagnose A No-Start Condition)
    https://forums.holley.com/showthread...7531#post77531 (Closed Loop Datalog Tuning - Posts #2, #4 & #6)

    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

    Default

    I'll try to get a good datalog using my laptop so I can Overlay while driving. I've tried enriching up those areas that are problematic, but I had a very funky Base Fuel Table.

    I've always cruised my engines at 14.7 AFR. I just tried enriching to 14.4, didn't seem to help. This morning I tried pulling the reference line to the fuel pressure regulator, it was solid 43 psi. Still had the same issues. I then forced it OPEN Loop only and the issue didn't seem like it was present. So I would assume this is more WBO2 or pre WBO2 exhaust leak that only seems to affect the engine in this region. Possibly a constant low map condition the exhaust is pulling in just enough air to mess the WBO2 sensor up? If I don't shift to 3000+ RPM or upshift and keep the engine under 2000 RPM the issue seems to go away. Jay

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,709

    Default

    Quote Originally Posted by jay_rich View Post
    I'll try to get a good datalog using my laptop so I can overlay while driving.
    What? There's no Overlay while driving because the live cursor indicates where you are while "Online" with the ECU.

    I then forced it OPEN Loop only and the issue didn't seem like it was present. So I would assume this is more WBO2 or pre WBO2 exhaust leak that only seems to affect the engine in this region.
    Please ensure there are no exhaust leaks upstream of the WBO2 sensor.
    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. #5

    Default

    Sorry more or less meant to watch where it is in the cells, not Overlay. I grabbed some more data on my way home from work. I'll Overlay shortly. Everywhere but 30-40 kPa on the ride home was perfect. Made a few 12 psi pulls zero issues, idles down perfect. Drives like a stock car, besides this darn cell!

  6. #6
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,709

    Default

    Quote Originally Posted by jay_rich View Post
    Everywhere but 30-40 kPa on the ride home was perfect.
    Knowing the problem area is half the battle. With this knowledge, pay attention to the paragraph in blue print below:

    Originally Posted by Danny Cabral
    Quick Datalogger Information:
    Always provide data, not just symptoms. Is the AFR & ignition timing optimized? Overlay the datalog onto your Global File.
    Ensure the Target A/F Ratio table is properly programmed for your engine. Ensure the ECU is "Learning" (Learn Table LINK).
    Scroll through the datalog to the problem area. Then look exactly where this happens on the Base Fuel & Timing Tables. Scrutinize:
    RPM, MAP, MAT, TPS, CTS, IAC, Target AFR, AFR Left, CL Comp, Ignition Timing, Duty Cycle, Fuel Flow, Fuel Pressure & Battery.

    Using the Holley EFI software (LINK), look at where the live cursor moves to during this occurrence, and
    manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing).


    I find the most helpful datalog function, is overlaying the datalog on your Global File.
    I'm in the habit of using the datalog Overlay feature every time I review a datalog.
    Click on "Datalog" (on the top Toolbar), "Activate Overlay", then "Open Data Log".
    You can literally "playback" a recorded event, and watch it as it happened on any screen.
    Minimize (shrink) the datalog window, and move it to the bottom of any Global File screen.
    Then click & scroll anywhere on the datalog, and watch it playback on your Global File (EFI software).
    http://documents.holley.com/techlibr...9r10543rev.pdf (Holley EFI Datalogger Instructions)
    https://forums.holley.com/showthread...s-amp-Datalogs (Datalog & System Log Information - Read "NOTES")
    https://www.youtube.com/watch?v=iqHO...C6FEA0BB99AF17 (How To Record & Email A Datalog)
    https://www.youtube.com/watch?v=q7OZUXLRS1Q (How To Record A System Log & Diagnose A No-Start Condition)
    https://forums.holley.com/showthread...7531#post77531 (Closed Loop Datalog Tuning - Posts #2, #4 & #6)
    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. #7
    Join Date
    Nov 2014
    Location
    Ont. Canada
    Posts
    1,388

    Default

    Use the Advanced Control Setting to slow down the CL. Sometimes the Closed Loop can be too fast and overshoots your Target A/F Ratio and then the oscillating starts.

  8. #8

    Default

    So I spend hours Overlaying, didn't really see anything catching my eye. Decided since it's a five minute job, I swapped back to my Siemens 80 lb/hr since they're way more than enough injector for my setup. The issues appears it has went away. Some more injector tuning must have been needed. But I'll continue testing this week to see if it has 100% went away, only had time for a quick spin today. Jay

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