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

Backfires - then it doesn't

Discussion in 'Engine & Transmission' started by deeksy62, Feb 12, 2019.

  1. deeksy62

    deeksy62 Active Member

    Messages:
    642
    Location:
    Sawtell
    Good morning all, I have a 1974 Kombi with an 1800 motor, a couple of weeks ago it started to backfire, only when cold and under load. reset the points and it seemed OK. Then last week it did the same for a couple of days.
    I reset the points again, they did seem OK though.
    Still backfires throught he exhaust and has no power under full throttle.
    Once it warmed up it was OK. Was thinking it may have been a exhaust leak?
    Now it has been running well for the past week.
    Maybe poor fuel?
    Blockage in the carbi?

    Or do I not look a gift horse in the mouth and accept that it is now going OK?

    Usually I would take it to Graham Melling at Mid Coast Volkwerks, but he has retired.

    So looking to the collective knowledge of the Kombiclub.

    Cheers

    Steve
     
  2. Barry

    Barry Well-Known Member

    Messages:
    3,020
    Location:
    Abbotsford NSW
    If you reset the points and it fixed it I would say that is your problem.

    My guess that the points are crap.

    I have seen points where there was no spring whatsoever in them and just flopped around.

    Try getting a new set of points
     
  3. deeksy62

    deeksy62 Active Member

    Messages:
    642
    Location:
    Sawtell
    Cheers Barry, will give the new points try a go!

    Steve
     
  4. grumble

    grumble Active Member

    Messages:
    938
    Location:
    Taree
    Change the condenser too as they are also well known to cause an intermittent spark. With new points set correctly 47-53 degrees dwell and the timing set, check inside the cap for tracking or condensation (moisture) when cold. Another cause can be a loose wire on the coil giving intermittent contact.
     
  5. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,402
    Location:
    Melbourne Bend of Islands
    The wonders of Kombi!
     
  6. deeksy62

    deeksy62 Active Member

    Messages:
    642
    Location:
    Sawtell
    Thanks Grumble.

    "The Kombi of Wonders" maybe more appropriate Alpal.
     
    Barry likes this.
  7. deeksy62

    deeksy62 Active Member

    Messages:
    642
    Location:
    Sawtell
    Quick update, maybe problem solved.
    A new tank of fuel, seems to be a bit better, BUT!!!! The cut off solenoid on the drivers side carbi was a little loose, so a quick tighten and it seems to be much better.
    Question: would a loose solenoid create a vacuum leak that would make it run poorly?

    Thanks

    Steve
     
  8. cbus

    cbus Well-Known Member

    Messages:
    11,263
    Location:
    sunshine coast
    Last edited: Feb 13, 2019
    deeksy62 likes this.
  9. grumble

    grumble Active Member

    Messages:
    938
    Location:
    Taree
    Yes the loose solenoid will let the engine run rich, this is also a common thing and occasionally the thread is worn so badly that the solenoid falls out. There are a lot of points that need checking in the carburettor system.
     
    deeksy62 likes this.
  10. Barry

    Barry Well-Known Member

    Messages:
    3,020
    Location:
    Abbotsford NSW
    Might be a good idea for a retune of the carbs as now you fixed something it may have masked other settings
     
    deeksy62 likes this.

Share This Page