Our other aircooled running issues

Discussion in 'General Discussion' started by the 3 crispies, Jan 8, 2021.

  1. BEETLE, 1600 sp newly rebuilt, ultra sonic cleaned icts and fully serviced, oem pump, malpassi reg and Cb manifolds. Sorry to run off subject but rebuilt our beetle nearly identical engine wise to our camper. But just cant fine tune running/starting issues. I can leave camper for a month and it fires up whereas this just wont.
    To start from cold (garaged) struggles to fire up and every press of gas pedal nearly stalls, once warm after 5 mins it starts and ticks over. Obviously the 34icts are never at their best on cold start. Only issue once warm is slight hesitation.


    Any ideas ?

    Planning tomorrow tweak mixture and try another fuel pressure gauge to compare if its true 2.5psi.

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    Last edited: Jan 8, 2021
  2. mikedjames

    mikedjames Supporter

    Vacuum advance not working?
    That Beetle distributor looks like it is very new and might be sticky or have a stiffer advance than expected. Might be all the difference it needs.
     
  3. Good shout will test that too but wouldnt that not of shown up when timing at max advance...

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  4. docjohn

    docjohn Supporter

    Might do, but it depends at what point it's sticking. You may have too much advance at cranking speed.
     
  5. docjohn

    docjohn Supporter

    Manifold air leak?
     
  6. Cold starting though ?

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  7. docjohn

    docjohn Supporter

    You need a rich mixture and retarded timing on cold start. If you are down on one then it is tricky, if you are well off on both then you'd be lucky to get it to fire at all. Does it fire OK if you spray Easy Start down the carbs?
     
  8. Dont know but sounds like a cold start problem the carbs you have dont have chokes do they ? i would look at the mixture or idle jetting
     
  9. davidoft

    davidoft Sponsor

    And here’s the lessons of old cars

    build 2 apparently identical things only to get a different outcome :eek:
     
  10. Our van with twin ICT’s is the same when it’s below about 3C. It’s due to no chokes. Usually needs 3-4 pumps of the pedal. It then fires up due to the extra gas from the accelerator pumps. However it won’t respond to the throttle for about 15-30 seconds while it warms slightly.
    Don’t have an issue with flat spots.
    I would recommend a 123 distributor however if you can run to it. Smoothes the slow running a treat. :thumbsup:
    Are you running the original distributor or is it an aftermarket one? I had big issues with an Accuspark one a few years ago. I removed it & filed it under B.I.N.
     
    Last edited: Jan 8, 2021
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  11. 77 Westy

    77 Westy Supporter

    He bought an Accuspark from me just over a year ago; it was working perfectly when I removed it but apparently it didn’t work when he received it. I believe he has fitted a new module but I don’t know if it’s on the Beetle engine.
     
  12. Dubs

    Dubs Sponsor supporter extraordinaire

    Given that it started fine in the summer, it sounds like it’s too weak to me. Double / treble check for manifold leaks, especially around the one that you had to file down Kev.

    If no leaks found, try going up a size on the idle jets. And do check the vac advance as suggested above.
     
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  13. Ha ha them manifolds couldnt see any leaks with leak spray or change in engine sorted fuel psi but sounds to me on 3 cylinders. Removed leads separately and no change in engine tone and strong spark. Turned mixture a little.//cloud.tapatalk.com/s/5ff9b0c7ea571/20210109_125107.mp4

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  14. Yes for bug, cant remember which module @Dubs replaced it with tbh.

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  15. Advance checked and working

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  16. I was told that when you start from cold gas pedal down all the way until it starts, worked for me, yeah
    every time to pump the gas pedal your flooding the Carb. @davidoft advice please.
     
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  17. Idles 55, mains 145, emulsions F6, 165 air,
    Float needles 150s at 8mm.
    Just found my notes when built carbs. Up idles to 57 ?

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  18. Dubs

    Dubs Sponsor supporter extraordinaire

    Foot to the floor is hot start procedure mate. Or if you have flooded it.
     
  19. Dubs

    Dubs Sponsor supporter extraordinaire

    That’s what I would do if you are 100% there are no air leaks
     
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  20. Dubs

    Dubs Sponsor supporter extraordinaire

    Oh, also, double check that both pump jets squirt when you operate the throttle. (Engine off)
     

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