No electronic scanner - How do u determine which ignition coil needs to be replaced?

Discussion in 'Engine Tech' started by gendong, Jun 13, 2016.

  1. gendong

    gendong Moderator
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    Here is the scenario:
    You are travelling on the highway, travelling long distance to ur hometown. Suddenly, ur engine becomes sluggish and power is lost, and u know its misfiring. Most of the time, the ignition coil is the culprit. U stop at the nearest lay-by/R&R to troubleshoot the issue as u hv a spare ignition coil in the trunk (perhaps a spare etc.). Problem is, u dont hv those handy INPA/scanner or any other device that can help u diagnose or help u determine which coil/cylinder is giving u that issue.

    Question:
    How do u determine which coil at fault? U do not have any assistance and u need to change it to get underway.
     
  2. unstopables_7

    unstopables_7 Official Member

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    lift up one by one (the coils) while engine is running and which coils you feel upon lifting up there is no difference in idling that's the culprit .. not sure whether is the right way but this is how i usually do.
     
  3. gendong

    gendong Moderator
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    thanks bro. guess thats how its done normally. any other methods?
     
  4. jarance

    jarance Moderator

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    Remove the spark plug and check which one is wet..
     
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  5. jarance

    jarance Moderator

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    Normally disconnect the LV plug side would be easier rather than lifting the coil.
     
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  6. gendong

    gendong Moderator
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    thanks Jarance for your insights...
     
  7. Joewong

    Joewong Club Guest

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    Hi there, I have some misfire while idling after my software has been updated to version B3.41.CO due to faulty fuel pump ECU. The mechanic not able to trace using the scanner.

    Does it generally means is the ignition coil problem or the spark plug? Could it be the new software update problem?

    Sorry I'm newbie and need some advise. TQ.

    Sent from my Nexus 6P using Tapatalk
     
  8. Joewong

    Joewong Club Guest

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    By the way, I'm on e90 323i LCI

    Sent from my Nexus 6P using Tapatalk
     
  9. jarance

    jarance Moderator

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    Why do you need to update software when you have a faulty fuel pump? Which workshop is that?

    It would be advisable to revert back to original version and work from there
     
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  10. Joewong

    Joewong Club Guest

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    Apparently the software version is not able to revert now. That's what I understand. The workshop is at Batu caves.

    Sent from my Nexus 6P using Tapatalk
     
  11. Joewong

    Joewong Club Guest

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    To add on, I'm ok with the software update as I can feel the car smoother. But some of the features ie. Door locks, speed limiter is not longer there and even the check fault which was previously exist in e90 no longer available.

    I'm little worried and confused. Will the new software helps much in terms of the ride.

    Sent from my Nexus 6P using Tapatalk
     
  12. Herbert

    Herbert Well-Known Member

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    Go back to the workshop that did the software update and ask them to re-instate the speed limiter, check fault etc. A very simple procedure to click the check box for these features.
     
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  13. Joewong

    Joewong Club Guest

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    Thanks Herbert.
    Appreciate it.

    Sent from my Nexus 6P using Tapatalk
     
  14. Mel279

    Mel279 Club Guest

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    And swap the good coil with the bad one just to make sure whether is it the coil or spark plug the culprit
     
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