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Thread: crank relearn

  1. #1
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    Default crank relearn

    Guys,

    I installed 03' LS1 engine on an old car, I also upgraded the PCM to 03' operating system (12225074). I can't do crank relearn, and the car doesn't move right and the timing fluctuates from 9 to 22 in idle.
    The trans is an old one and not connected to the pcm, and the OS is set for manual in order to avoid any cal confusion.

    Do you think that the crank relearn will cause this problem? if not, would you tell me what would cause the timing to play that much??? And is there any thing can relearn the crank angle manually?
    Regards,

    Odd Boy

  2. #2
    EFILive Crew Site Admin Tordne's Avatar
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    That OS was used in the Holden Commodore vehicles. If you're using it on a Camaro (just from looking at your avatar) then you should use OS # 12212156 instead. There is some operating system specific code (which cannot be changed) which might cause issues.
    Andrew
    EFILive Crew


  3. #3
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    The engine is for commodore. can u help me to resolve the timing issue??
    Regards,

    Odd Boy

  4. #4
    EFILive Crew Site Admin Tordne's Avatar
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    There could be so many causes for timing. As you are no doubt aware looking at the calibration there are many tables which add/subtract timing based on various conditions:
    - IAT/ECT Temps
    - RPM deviation from desired idle
    - Spark smoothing

    Best bet is probably to log a bunch of spark related PIDs and see if you can derive which of them is contributing the the fluctuation.
    Andrew
    EFILive Crew


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    Quote Originally Posted by Tordne View Post
    - RPM deviation from desired idle
    what would cause that? what will hapen if the C.A.S.E is not relearned? will it affect the car performance or it won't find misfire if there is any?????
    Regards,

    Odd Boy

  6. #6
    Joe (Moderator) joecar's Avatar
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    CASE is used for misfire detection... it shouldn't affect engine performance... something else is wrong, but you should see if you can do a CASE relearn anyway.

  7. #7
    EFILive Developer Site Admin Blacky's Avatar
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    When you see timing swinging at idle, usually it is a response to some other issue, not the cause. The PCM will adjust the timing (a lot) to try to stabilize the idle at the desired idle setting(s).

    Something as simple as a blocked fuel filter/injector (or anything that can cause fuel delivery problems) can cause the idle to change and therefor cause the PCM to drastically alter timing to try to correct the problem.
    Running too lean at idle will cause surging.

    Have you tried programming in a 100% stock tune?

    Is the engine modified? Different cam? Different intake? Still using a MAF? Is the IAT sensor connected and working?

    Are there any trouble codes set? Have you disabled any trouble codes?
    What are the test results for "specifically monitored systems"?
    What are you fuel trims at idle? Are they similar for both banks?

    Regards
    Paul
    Before asking for help, please read this.

  8. #8
    EFILive Crew Site Admin Tordne's Avatar
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    Also too much airflow at idle might be making the idle race a bit and the spark will fluctuate to try and compensate. Logging the spark PIDs might allow you to determine which of the spark modifiers is being invoked.
    Andrew
    EFILive Crew


  9. #9
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    Quote Originally Posted by Blacky View Post
    Something as simple as a blocked fuel filter/injector (or anything that can cause fuel delivery problems) can cause the idle to change and therefor cause the PCM to drastically alter timing to try to correct the problem.
    Running too lean at idle will cause surging.
    new filter, injectors, and fuel pump were installed recently, I'll check the fuel pressure in order to clear up the doubt
    Quote Originally Posted by Blacky View Post
    Have you tried programming in a 100% stock tune?
    The engine is 2003 (we name it Caprice here in the middle east) has the same engine of commodore but the body of the car is bigger. The PCM I've got is for the same car but 2000, I installed the stock tuning file of commodore 2003
    Quote Originally Posted by Blacky View Post
    Is the engine modified? Different cam? Different intake? Still using a MAF? Is the IAT sensor connected and working?
    it is stock engine, and the MAF is there and doesn't make any deference, I keep it or remove it the car does the same. The IAT is there and working.

    Quote Originally Posted by Blacky View Post
    Are there any trouble codes set?
    yes there is one for low pressure, which i guess has nothing to do with this case. Before installing OS of 2003, the MAF P0102 was on while the and its cables were checked and found okay

    Quote Originally Posted by Blacky View Post
    Have you disabled any trouble codes?
    nope

    Quote Originally Posted by Blacky View Post
    What are the test results for "specifically monitored systems"?
    I guess you mean cyl test, some times cyl 6 is week.

    Quote Originally Posted by Blacky View Post
    What are you fuel trims at idle? Are they similar for both banks?
    I disable them, since I want the car to be in open loop all the time.

    You know when I press the accelerator fully or partially at idle or while driving, the car gets strangled and moves like a 1 cyl car
    Last edited by odd boy; August 25th, 2008 at 06:05 PM.
    Regards,

    Odd Boy

  10. #10
    EFILive Developer Site Admin Blacky's Avatar
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    Quote Originally Posted by odd boy View Post
    You know when I press the accelerator fully or partially at idle or while driving, the car gets strangled and moves like a 1 cyl car
    Can you please log the following PIDs:

    SAE.TP
    SAE.RPM
    SAE.MAP
    SAE.MAF
    SAE.IAT
    SAE.ECT
    SAE.SPARKADV
    GM.AFR
    GM.IBPW1
    GM.IBPW2
    GM.DYNCYLAIR
    GM.CYLAIR_DMA
    GM.EST_IAC_DMA
    GM.EST_ECT_DMA

    Get engine to operating temperature (about 85 degC ECT or above). Stat logging, leave it at idle for about 5-10 seconds, then slowly increase the throttle position to about 20-30% over about 5 seconds, then let it return to idle for about 5-10 seconds. Stop logging.

    Then post the *.efi log file in this thread.

    Regards
    Paul
    Before asking for help, please read this.

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