e36 m50 misfire and lack of power

Thread in 'Technical Questions' started by chicane1992, Mar 28, 2015.

  1. chicane1992

    chicane1992 Member

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    My m50 has suddenly developed a large misfire. A big Loss in power aswell. It only does it when the engine is warm. Anybody got any idea what it could be?
     
  2. Andy318ti

    Andy318ti Active Member

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    Headgasket?
    Has the coolant level dropped?
     
  3. chicane1992

    chicane1992 Member

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    Coolant is fine. Have ruled out HG as its got no symptoms pointing to that. And it's fairly low mileage. thinking possibly coilpack.
     
  4. A32 Hero

    A32 Hero Member

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    I've got this problem on an m52 engine and it's also definitely not HG, it's most likely either coilpack or injector.

    I previously solved the problem by replacing the coil pack about a month ago, but recently a coolant hose split and got everything slightly wet - dried it all out and replaced the coil on the cylinder that was missfiring yet still does it, so i'm saying injector.
     
  5. LiamE36

    LiamE36 Active Member

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    Probably worth locating which cylinder is miss firing first.

    Then try the obvious things, coil pack, spark plug, injector.
    If none of them work carry out a compression test.
    If that is all good and it's still temp related try a coolant temperature sensor. If that still doesn't do it then it's probably worth getting hold of some diagnostic gear and having a look at the live data to see what's happening.
    M50's do shit out ecu's every now and then, I've had two die in the space of a year before.
     
  6. chicane1992

    chicane1992 Member

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    Cheers mate, gunna get it hooked up in the week and see what cylinder is mis firing. It's a very intermittent mis fire. Comes and goes whilst driving. When it does happen it's pretty rough though.
     
  7. chicane1992

    chicane1992 Member

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    Also how did you get around using your 328 maf with your 325? When I plug the 328 maf in the engine goes mad. The 325 dosent fit
     
  8. LiamE36

    LiamE36 Active Member

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    M52's and M50's have different MAF's so it won't fit, who said they fitted one?

    Sounds like your MAF is fooked. I'm using a 328 at the moment with a faulty MAF sensor, usually holding its revs on idle between 1300 and 1900 rpm.
     
  9. chicane1992

    chicane1992 Member

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    Sorry thought in a previous thread you said you was running an m50 conversation aswell. I'm running mafless atm. have had no problems at all so far until now. Runs abit rich but that's it.
     
  10. chicane1992

    chicane1992 Member

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    Garage couldnt get a read out from my ecu using diagnostics. Any suggestions? Change spark plugs? See what happens?
     
  11. LiamE36

    LiamE36 Active Member

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    Why couldnt they read it?

    Some diagnostic tools don't like the converter lead that links the diagnostic tool to the 20 pin round diagnostic plug on a 36.
     
  12. chicane1992

    chicane1992 Member

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    No idea mate, kept coming up with no system found. Gunna try some bits tomorrow. See if that makes the problem any better
     
  13. bell

    bell Without patience

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    daft as it sounds temp sensor. we had this on an m50 non vanos and it wouldnt show up on a diagnostic either.
     
  14. chicane1992

    chicane1992 Member

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    Yeah that was a suspicion of mine. Changed the spark plugs and everything seems OK atm. They were pretty shot haven't changed them since I got the engine so my fault. Just going to wait and see if it comes back
     

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