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SOLVING LOW IDLE

Discussion in '308/328' started by absostone, Jul 28, 2019.

  1. absostone

    absostone F1 Rookie
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    How the hell could a pro shop familiar with these carbs screw this up so bad and still run good?
     
  2. Saabguy

    Saabguy Formula 3
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    Yeah but at this point you need to get to a good starting point.

     
  3. Saabguy

    Saabguy Formula 3
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    Status? Did you give up on the whole thing and buy a Tesla? ;-)
     
  4. absostone

    absostone F1 Rookie
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    Thinking about it. I tried again and there is no increase in rpms even at 7 turns out. I decided to put it back to the turns I had written down. Decided to check timing. It’s jumping all over the place. But it idles steady. Total mess
     
  5. Saabguy

    Saabguy Formula 3
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    That is what you want, that means that you were close to the ideal mixture IF you had disconnect all of the connecting rods, making it richer DOES NOT increase idle speed if you are at the right mixture. But that only works if timing is solid. So you are back to where you started with everything. Gotta lock down the timing first. Isn't this fun!! o_O
     
  6. absostone

    absostone F1 Rookie
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    Not fun. I thought to myself there is no way the mixture is perfect.
     
  7. absostone

    absostone F1 Rookie
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    New cars temporarily solve carb issues in other cars. I’m intrigued by the electric carbs In The Tesla ,wink wink
     
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  8. absostone

    absostone F1 Rookie
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    Let it b known to all DIYers that trying to set timing with spark plugs that have had the mixture screws twisted full on and full off for a week will give you jumpy timing marks. !
     
  9. absostone

    absostone F1 Rookie
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    Both banks as close as possible to 7 degrees!
     
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  10. absostone

    absostone F1 Rookie
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    Ok so haven’t worked on it in a while. Since my wife decided to redo my boys room. Which turned into redoing the entire second floor. I’m gonna try and redo the entire process today now that the timing is set
     
  11. Saabguy

    Saabguy Formula 3
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    It's always good to get away and take a fresh look at things , well ok, most of the time. ;-)
     
  12. absostone

    absostone F1 Rookie
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    Yup
     
  13. absostone

    absostone F1 Rookie
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    Well decided to install new caps and rotors. And they won’t seat. I’ve been avoiding buying new caps and rotors for like 10 yrs cause of the horror stories I’ve read about here. So I finally broke down and ordered them last month. And they ended up being a waste of time. Put the old magnettis back on and I’ll redo the carbs tomorrow SOB!
     
  14. absostone

    absostone F1 Rookie
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    Cable pulled to 1500rpm. All carbs at 7kg. Loosened cable to 1k set stops. Slacked cable idle at 1k. All carbs with all air bleeds closed exactly 5kg. Doesn’t look like it’s gonna go lower.
     
  15. absostone

    absostone F1 Rookie
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    Drove her to the Geneva Concours on Sunday. Idled well. There is some gurgling lean in the 3kto 3400 rpm range. But ran good. So what is the importance of having close to 3.5 kgh?
     
  16. absostone

    absostone F1 Rookie
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    Anyone explain, the need for the low kgh????????????????
     
  17. Steve Magnusson

    Steve Magnusson F1 World Champ
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    It's not a "need" -- it's the usual barrel airflow rate on a carbed 308 that is obtained IF all of the cylinders are actually contributing at idle. At ~5 Kg/hr and 1000 RPM, either:

    1. not all cylinders are contributing (running) at idle, or

    2. your Synchrometer is not calibrated.

    You have to be a little careful to do this (so do at your own risk), but, if you unplug each spark plug one at a time, the RPM should drop a little, and you should "hear" the miss of that cylinder. If you unplug a spark plug and nothing changes = that cylinder is not actually contributing at idle.
     
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  18. absostone

    absostone F1 Rookie
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    I get it. I’m gonna fool with it this weekend. But when I tried pulling wires earlier. Rpms drops were barely noticeable.
     

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