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Passenger Side Plugs Fouling / Ds Looks Good ??

Discussion in 'Early CJ5 and CJ6 Tech' started by Buildflycrash, Apr 1, 2020.

  1. Apr 1, 2020
    Buildflycrash

    Buildflycrash Member 2020 Sponsor

    Gulf Breeze FL...
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    Last weekend wife and I were trail riding for several hours. Power was down very noticeably by the end of the trip. Maybe 3hrs of mostly low speed / low RPM bumping along. I cleaned these up, re-gapped and reinstalled. Also put in Pentronix ignition that was sitting on my shelf of several months. Everything is much better this week.

    But why did the passenger side load up so bad and driver side looks pretty good? Dauntless V6....

    [​IMG]


    [​IMG]
     
  2. Apr 1, 2020
    53A1

    53A1 Member

    Kern Co. Ca.
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    I would look at the others plugs on the PS. If they are all like that I would turn in the fuel mixture screw on that side 1/4 - 1/2 turn. If only one is fouled then start looking at other things. The DS looks great and the PS is not far off.
     
  3. Apr 1, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member 2020 Sponsor

    Denver, CO
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    I've been fighting this for 4 years...this is exactly what mine do - and I do a plug cleaning part way through every wheeling season to minimize the issue. In my case, I feel there is an issue with my exhaust causing a bit more back pressure on the passenger side (my exhaust manifolds are not the same design - and I probably have a poorly designed y-pipe where the two header pipes join). IIRC, the idle mix screws do not feed one bank each, but rather 2 on one side and one on the opposite side based on intake manifold design...in other words, the passenger side idle mix screw feed 2 cylinders on the passenger bank, and one cylinder on the driver bank - so if all 3 on the passenger side are fouling it would seem to me to be more than just the idle mix. I could be wrong....
     
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  4. Apr 1, 2020
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    Conventionally you are supposed to adjust both idle screws the same. If you want you can lean up idle generally. I'd first test that they are both turned out the same amount. Then I would run at idle and turn each in the same amount a bit at a time until the idle starts to stumble. Then back out just until it smooths out. This would be "best lean idle" and what Jeep specifies from ca '72 on.

    I would also test that the throttle plate is closing completely and that I had no vacuum leaks. You should be able to stall the engine by turning the idle mixture screws all the way in. You should also be able to stall the engine by backing out the idle stop screw to slow the engine. If either test fails, could be that you have a vacuum leak that favors one side, leaning it out.
     
  5. Apr 1, 2020
    Buildflycrash

    Buildflycrash Member 2020 Sponsor

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    O

    One of the plugs on DSide was clearly worse than the other two. I have no idea what screws are what and never have adjusted a carb - But what the hell - I'll shoot some photos and y'all can learn me!
     
  6. Apr 1, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member 2020 Sponsor

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    the idle mix screws are down low on the front of the carb - kind near the base....they are tucked up under the float bowl so not obvious at first...Just to make life easier, i usually remove the air filter housing so i can access it a bit easier.
     
  7. Apr 1, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member 2020 Sponsor

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    Here is a pic - this is looking at the passenger side of the carb - the fuel inlet is the line at the top. Under that is a nipple - its the ported vac that goes to the distributor. And under that is the passenger side idle mix screw (it has a coil spring wrapped around it)- there is a driver side one also on the front of the carb - but on the 'other' side (cannot be seen in the pic). Between the fuel inlet line, the radiator hose, the air cleaner housing, and the ported vac line - it usually takes an injured shoulder to twist your hand around to reach under there...They are slotted for a flat head screw driver, but I am too uncoordinated to do it that way...I prefer the shoulder injury and the burns on my hand from when the intake manifold gets hot. Make sure your timing is set the way you want, and the engine is warmed up before messing with the idle mix. Good luck
    [​IMG]
     
  8. Apr 1, 2020
    Buildflycrash

    Buildflycrash Member 2020 Sponsor

    Gulf Breeze FL...
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    My carb is similar, there are two screws w/ springs on the front.

    [​IMG]

    I mailed it off for rebuild last year.

    [​IMG]


    I guess I'll start with turning both all the way in and count the turns. Then start on the tests Tim posted above. I'll post my results. Thanks for everyone's help


    [​IMG]
     
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  9. Apr 1, 2020
    Beach66Bum

    Beach66Bum 1966 Tuxedo Park Mark IV 2020 Sponsor 2019 Sponsor

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    Do not tighten the air mixture screws tight! This can damage the fine needle point on them! Gentle turn them in till they just “seat”
    Then count 2 full turns out for each, this is a good bench mark to start with. A vacuum gauge is the tool to use.
     
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  10. Apr 1, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member 2020 Sponsor

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    I was just thinking of adding the 'do not tighten too much'...that is truly the reason i use my fingers to adjust the screws as it was easier to feel when they seated without damaging....
     
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  11. Apr 1, 2020
    Beach66Bum

    Beach66Bum 1966 Tuxedo Park Mark IV 2020 Sponsor 2019 Sponsor

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    Yes! Exactly. I have a parts Rochester 2G where someone tighten the screws so tight in that it actually damaged the carb lower base, enlarged the actual holes!! :n::steamed:
     
  12. Apr 1, 2020
    Twin2

    Twin2 not him 2020 Sponsor 2019 Sponsor

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    idle screws . you need a old school tool
    idle adjusting tool - Copy.JPG
    idle adjusting tol knob - Copy.JPG
     
    Last edited: Apr 1, 2020
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  13. Apr 1, 2020
    Beach66Bum

    Beach66Bum 1966 Tuxedo Park Mark IV 2020 Sponsor 2019 Sponsor

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  14. Apr 1, 2020
    Rich M.

    Rich M. Shoe pusher

    Maryland
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    I second using a vacuum gauge to tune.
     
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  15. Apr 1, 2020
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
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    I was having issues fouling three of the plugs and the others being good. Wrong distributor cap was the culprit. There are 3 for the Dauntless if I remember correctly.
     
  16. Apr 1, 2020
    Buildflycrash

    Buildflycrash Member 2020 Sponsor

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    well how the heck would I know?
     
  17. Apr 1, 2020
    Buildflycrash

    Buildflycrash Member 2020 Sponsor

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    I got home from work a little late so I just checked the screws. Both were out just over 3turns. I set them at 2.5 turns out then spent the rest of the evening cleaning guns.

    Florida went to “shelter in place” starting tomorrow so I’ll have plenty of extra time at home for the next few weeks.
     
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  18. Apr 2, 2020
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
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    I had to order all 3 and try them individually. I ruled out the prestolite pretty easily. it doesn't have the window for adjusting dwell. The two Delco ones will be your choices then. If there are 2 different Delco rotors, order both but keep them with their corresponding caps. Try 1, drive it. Notice the smoothness and power level. Try the 2nd one. Same deal. It will be apparent. I imagine you could also throw on a vacuum gauge and whatever one reads more vacuum, will probably be the correct cap and rotor. Apparently the earlier points Delcos (up to 1967) had a different cap than the later, (68 and later) cap. Also the inline 6 Chevys of that era had a cap that would fit but not be correct. It was in the clocking of the cap that they were different.
     
    Last edited: Apr 2, 2020
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  19. Apr 2, 2020
    fhoehle

    fhoehle Sponsor

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    Keep in mind that the difference is not huge. The Dauntless will run, but it won't seem "right". I would consistently, but not really quickly foul 3 plugs and the exhaust smelled a little gassy. When you have the two different Cap combinations tried one after the other, it will be pretty easy to figure out which one works for your engine. Be friends with your parts guy and explain your predicament and I would bet they would take the wrong parts back when you get it figured out. The problem was a real head scratcher for me.
     
  20. Apr 2, 2020
    colojeepguy

    colojeepguy Colorado Springs 2019 Sponsor

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    James is correct here...this is called a dual plane intake manifold & it's how almost all V-type engines are set up.
     

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