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Timing question

Discussion in 'Fuel System & Electrics' started by Burnstar, Aug 17, 2015.

  1. Burnstar

    Burnstar Member

    Messages:
    98
    Location:
    Artarmon
    My 74 Kombi, 1800cc is spluttering a bit. I just changed the spark plugs to Bosch WR7CC (the shop didn't have the NGK B7ES) and it is running better but still spluttering I probably need to change the ignition leads as the N0. 4 lead came off the rubber plug.. (I did grab it properly to pull it out)

    However when I checked the timing it is set on TDC, yeah everything I've read says 7.5 BTDC is there any possible reason why I shouldn't change it to 7.5BTDC ?

    Also since I have electronic ignition can I just use original spec leads or do I need something else?
     
  2. Burnstar

    Burnstar Member

    Messages:
    98
    Location:
    Artarmon
    I've just been reminded to unplug the vacuum advance tube before checking the timing, the memories of checking the timing on dad's XB falcon in the 80's are slowly coming back...
     
  3. Barry

    Barry Well-Known Member

    Messages:
    5,862
    Location:
    Abbotsford NSW
    Make sure your valves have seen set first

    Also make sure all cylinders are firing.

    Carefully - pull each lead one at a time at the distributor
    You should hear the revs drop

    I am a Type 1 person - but I believe 7.5BTDC is correct your a Type 4 1800
     
  4. saabman

    saabman Well-Known Member

    Messages:
    4,888
    Location:
    Goulburn
    It should be 7.5deg before tdc.

    Set it with the engine off with a test light or buzzer (static timing)

    Or use your timing light at idle with vacuum line disconnected.
    If you leave the vacuum line connected it will still be no where near 0deg.

    At about 3000 rpm the timing should increase to around 30deg.

    I don't have the exact figure on hand but if your getting up around 30 it should be ok.
     
  5. Burnstar

    Burnstar Member

    Messages:
    98
    Location:
    Artarmon
    I thought I'd better update the resolution on this, the mechanic fixed it for me.
    It turns out the negative earth strap was loose which was causing the initial spluttering.

    However with the Bosch WR7CC plugs it was backfiring and once I changed to the NGK-B6ES the backfiring went away.
    The mechanic also adjusted the carbies to make it run smoother however he advised that the right hand one needs reconditioning (meaning they both need to be done) as the carbie throtlle shafts are worn.
     
    cbus likes this.
  6. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,983
    Location:
    Melbourne Bend of Islands
    And did you retime to 7.5?
     
  7. Burnstar

    Burnstar Member

    Messages:
    98
    Location:
    Artarmon
    The timing wasn't actually out, it's still on 7.5 (although I haven't checked since going back to NGK as I had to fix the timing gun as the trigger broke...)
     
  8. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,983
    Location:
    Melbourne Bend of Islands
    Found that balancing the carbs is a good move.
     
  9. saabman

    saabman Well-Known Member

    Messages:
    4,888
    Location:
    Goulburn
    get the carbies redone - its not terribly expensive and worthevery cent -

    It will make the van run so much betetr youll wonder why you didnt get itdone ages ago.

    CBB at penrith do a great job, from memory I think it was around $500 or $600.
     
  10. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,994
    Location:
    Penna, Hobart
    As has been said in a few other threads the Bosch plugs are now made in India and the quality has gone south. The NGK are still Japanese and are superior.

    Adrian
     

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