Welcome to ZRoadster.org - BMW Z1 Z4 Z8 Z3 Forum and Technical Database

If you want to join in with the discussion, and see the areas which are available only to members then sign up now!

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Misfire on cyl 2

Discussion in 'Z3 & Z3 M Roadster & Coupé Knowledgebase' started by board, Jun 29, 2014.

  1. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    Jumped in the car today to nip out and was running really rough so cancelled nipping out and got the computer out.

    Found that cyl 2 was not firing according to the diags so decided to lift the cover to inspect what was going on. The car was serviced a few weeks ago and hasn't done many miles since, on lifting the cover I was greeted with this:
    image.jpg

    Which shows the number 2 lead was not put back in its cable tray and has subsequently been crushed by the cover. I have swapped number 1 and 2 coil packs round, cleared the codes, in order to double check those and the error remains on number 2. The plug is nice and clean.

    My question is, does anyone know if it is possible to replace the lead without replacing the whole harness as from the little inspection I did it does not look like a simple unplug old and plugin new?

    I can only think that this is the issue unless anyone has any other suggestions?

    Thanks,
    James
     
  2. badman gee

    badman gee Guest

    Hello james.

    I take it that that area of the car wasn't touched during the recent service?

    I'm not sure if the cables are individual or part of a loom.
     
  3. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    Inspection I, so they should have had it apart for the new plugs. I'm going to be calling them first thing to have a chat but trying to find out what the damage is likely to be, I don't know how sensitive the cables are but suspect they don't do too well with being squashed with the cover.
     
  4. badman gee

    badman gee Guest

    Well it's possibly down to them.

    No other reason for it to be trapped.
     
    • Agree Agree x 2
  5. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    I'm hoping the cables can be replaced individually but I have a horrible feeling they can't and that's going to be expensive, I will have to see what the guy says tomorrow. Sod's law I have a long journey Tuesday and need the car.
     
  6. badman gee

    badman gee Guest

    Good luck james.
     
  7. t-tony

    t-tony Zorg Expert (I)
    Supporter British Zeds #ZedShed

    Joined:
    Dec 31, 2013
    Messages:
    31,132
    Likes Received:
    14,718
    Trophy Points:
    220
    Location:
    Torksey Lock,Lincoln, England
    Model of Z:
    Z4 3.0 Auto
    James, it may be possible to solder in a new piece of cable for the ignition coil with connector, rather than having to replace the whole lead set or loom.Repair sections may even be available from BMW?
     
  8. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    I'm hoping that is the case, not having had one apart before I have no idea how they are connected.
     
  9. t-tony

    t-tony Zorg Expert (I)
    Supporter British Zeds #ZedShed

    Joined:
    Dec 31, 2013
    Messages:
    31,132
    Likes Received:
    14,718
    Trophy Points:
    220
    Location:
    Torksey Lock,Lincoln, England
    Model of Z:
    Z4 3.0 Auto
    Good luck with it. If I can help pm me.
     
  10. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    Thanks Tony and Mark, I'll let you know how I get on tomorrow. I just checked and the car has done 1035 miles since the service. I guess the compression from the heating and cooling damaged the lead.
     
  11. badman gee

    badman gee Guest

    Keep us updated sir
     
  12. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    Update. The service guys very kindly came out at short notice and had a good look round. We tested everything and it turned out with his computer that cyl 6 was not firing. We swapped everything round and did a test on the spark using his computer but still nothing.

    I have now done continuity tests back to the ECU and all 3 wires are getting continuity back so it is looking like and ECU fault :(
     
  13. t-tony

    t-tony Zorg Expert (I)
    Supporter British Zeds #ZedShed

    Joined:
    Dec 31, 2013
    Messages:
    31,132
    Likes Received:
    14,718
    Trophy Points:
    220
    Location:
    Torksey Lock,Lincoln, England
    Model of Z:
    Z4 3.0 Auto
    Bad news there James. Hope it doesn't turn out expensive.
     
  14. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    Thanks tony. Trying to find a way of getting it tested, I have had a name of loom doctor given to me who comes out with an oscilloscope but can't find any details. I haven't got a trailer to put it on to take anywhere so it's becoming a challenge.
     
  15. badman gee

    badman gee Guest

    Hope you get it sorted james.
     
  16. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    I'll get there, just annoying with this lovely weather and the one day I have a long drive ahead down some twisty roads and it decides not to play. The guys at the garage were excellent by the way, despite my thinking that it was something they had done and was not, they did not charge for the call out and were spot on while working on it.
     
    • Like Like x 2
  17. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    I must add, this is the first time it has let me down in the 14 or 15 years I have owned the car so not complaining
     
    • Like Like x 2
  18. board

    board Administrator
    Staff Member Administrator Global Moderator British Zeds M Power

    Joined:
    Dec 2, 2011
    Messages:
    1,379
    Likes Received:
    68
    Trophy Points:
    88
    Location:
    Cuiaba
    Model of Z:
    M Roadster
    Quick update.

    Good news, back on the road :)

    Turns out it was the ECU which had a fault so sent it off to http://www.the-ecu-doctor.co.uk/ who received the unit on Tuesday and had it back to me repaired on Friday. They pulled the info from it which showed the coil pack was failing on Cyl 6 which had in turn caused the issue with the ECU. So new coil packs were ordered, refitted the repaired ECU and now running perfectly again.

    I am pleased to report a top service from the local garage (my initial grumble being an incorrect diagnosis, they would not let me pay for the call out even though it was my fault), the ecu doctor and sopers for getting the coil packs in next day for me.
     
    • Like Like x 3
  19. hard top

    hard top Zorg Expert (I)
    Dutch Zeds The M44 Massive

    Joined:
    Dec 5, 2011
    Messages:
    20,779
    Likes Received:
    6,061
    Trophy Points:
    213
    Location:
    Netherlands
    Good news......:)
     
    • Agree Agree x 1

Share This Page