1776 engine miss fireing

Discussion in 'Mech Tech' started by christerry, Oct 20, 2019.

  1. Set dizzy up and pointing to no.1
    Turn engine over and it fires up but starts to miss fire through csrb

    Leads are at 1 4 3 2

    Any ideas please
     
  2. stirlingmoz

    stirlingmoz Supporter

    Well the firing order is correct.

    Are you running points or electronic ignition ?

    If points, are they in good condition and correctly gapped ?

    Condenser good ?

    Have you tried strobing it to check the timing ?

    I think any of these problems can cause poor running.


    Stirlingmoz
     
  3. PIE

    PIE

    Valve gaps can make it misfire through the carb
     
    mgbman and Day like this.
  4.  
    Last edited: Oct 20, 2019
  5. stirlingmoz

    stirlingmoz Supporter

    If it’s been stood a while, the fuel could have ‘gone off’ or be contaminated.

    You may have something as straight forward as a blocked idle jet in the carb or an air leak.

    The secret is to be methodical.

    Sounds like you have ruled out ignition problems, so fuel system is next.

    Stirlingmoz
     
    mgbman and Day like this.
  6. Have you set the ignition timing?
     
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  7. mikedjames

    mikedjames Supporter

    Timing setup properly please, before accusing the engine of being bad.

    Electronic points replacements can fail suddenly, if it runs with points then that could be the issue.

    Backfiring through carb can also be mixture related, too rich , it flooded with electronic ignition, you changed it , it ran for a bit and flooded again with points.. a leaky carburettor fuel valve can make a perfectly working engine mess around. It probably actually runs the same with electronic ignition.




    If you really have destroyed the engine after 800 miles ( 5 weeks driving for my bus), it must have been setup really badly by whoever did it.. mind you I have seen the output from a T2D installation effort and it was bad with a huge air leak, making it run lean and rough.

    Check compression to see if the valves are really a cause.
     
    Last edited: Oct 20, 2019
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  8. matty

    matty Supporter

    If you’ve changed the electronic ignition module and fitted points without moving your dissy it will be 90 degrees out.

    as others have said you need to set the timing
     
    Valveandy, christerry and mgbman like this.
  9. misfire through the carb, spitting out the top, could be your ignition leads are out of order. 1 4 3 2 in clockwise order looking down on the top of the dizzy cap. What's the story about the dizzy? When it fires up does it actually run or just spitting out the carb? Did you change the dizzy and why?
     
    snotty likes this.
  10. Thanks for all the replies and advice

    Points set correctly
    Timing is right
    Dizzy in correct
    It was flooded like a knob I tested the pump but silly me put the pipe into the throttle Chamber thus flooding the engine
     
    mikedjames likes this.
  11. Check for Vacuum leaks. These cause backfires up the carb too. You may hear a hissing sound or just spray carb cleaner on every gasket and hose.

    Also Vacuum leaks cause the exhaust to pop when the engine is hot.
     
  12. Brain picking time part 2 please

    Tried to start the engine today and it starts then after a few reves it starts to back fire
    Any clues please
     
  13. Part 2 started engine this morning starts and runs then back fires
    Immediately
    So off with carb then whoops no gasket betwen carb and and manifold
    I wonder if that's the problem
     
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  14. Unlikely. I reckon your ignition timing is well out of whack.
     
    Dubs likes this.
  15. Dubs

    Dubs Sponsor supporter extraordinaire

    It will pop and bang if there is a massive air leak due to the lack of gasket. Stick one on and try it. If it’s no better then likely a timing issue as snotty says.
     
  16. stirlingmoz

    stirlingmoz Supporter

    ooh do I win a prize ?

    It’s not often I get one right

    Stirlingmoz
     
  17. They can often twist and shout as well.
     
    Dubs likes this.
  18. Morning each
    Part 3 of dont wants start VW
    Battery fully charged
    Turn key and it turns over but stops dead
    Try again same thing happens
    Engine wont do more than one revolution
    It's a halfords battery
    510cca 62 ah 12v
    With 12.93 volts showing on mtr
    Any clues please
     
  19. Fuel filled the cylinders ? Starter not working?
     
  20. Dubs

    Dubs Sponsor supporter extraordinaire

    Sounds like timing too far advanced? Or hydraulic lock due to carb flooding?
     
    Patrick Nguyen and snotty like this.

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