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New Commando Owner, Cant #4 Cylinder To Fire

Discussion in 'Jeepster Commando and Commando Tech' started by stain, Apr 15, 2018.

  1. Apr 15, 2018
    stain

    stain New Member

    vt
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    Mar 4, 2018
    Messages:
    10
    Hi, new Commando owner here in VT
    I just sold my 78 Bronco and was looking to replace it when I came across this 68 Commando
    [​IMG]
    The picture looks better than it is, someone did not do a very good job on the paint.

    I bought knowing it wasn't running correctly and discovered the #4 plug to be soaked. I replaced plugs, swapped wires, checked timing checked compression---150 across the board. The cylinder has fire. All other plugs are fine. The carb has been rebuilt.
    I then thought the cam lobe for the exhaust may be worn. I checked the rocker movement with the adjoining cylinders and they seemed the same. I am stumped. I have heard of 1 exhaust manifold in my life being plugged in 1 cylinder causing a skip.
    My other question is this the original engine? It seems the heads have some air ports blocked off that were used for air injection and the heads have GM cast in them?
    [​IMG]
     
  2. Apr 15, 2018
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
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    not seeing picture
     
  3. Apr 15, 2018
    stain

    stain New Member

    vt
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    Mar 4, 2018
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    They seem to be there for me???
    It looks as though this problem has been going on for a while. Newer cap, rotor, condenser etc. You can see that the gasket on the #4 manifold gasket is wet. I might pull the right manifold off tomorrow....
     
  4. Apr 16, 2018
    masscj2a

    masscj2a Member 2023 Sponsor

    Ware, Mass
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    Dec 27, 2013
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    No pictures for me either. Congrats on the Commando. If you can bring up pictures it would help. Have the plug wires been replaced ? I would at least check for spark at the #4 hole. Maybe wire is no good. If that plug is wet that badly, it to may be gone. I would start there, wire, then new plug. Good luck and welcome to Jeeps :rofl:
     
  5. Apr 16, 2018
    stain

    stain New Member

    vt
    Joined:
    Mar 4, 2018
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    did that work?[​IMG]
     
    Last edited: Apr 16, 2018
  6. Apr 16, 2018
    stain

    stain New Member

    vt
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    Mar 4, 2018
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    any way I figured it out. I thought about it all day at work and thought it almost HAD to be an intake leak into the vally. Got home and pulled off the Intake and sure enogh the right side intake gasket was installed backwards.

    [​IMG]
     
  7. Apr 16, 2018
    stain

    stain New Member

    vt
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    Mar 4, 2018
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    Who knows how long this has been like this. It looks as though the intake has been there for a long while. At least the inside of the motor looks really clean.
     
  8. Apr 16, 2018
    baldjosh

    baldjosh Member

    pacific north west
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    Oct 24, 2017
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    worked for me...looks like a beauty
     
  9. Apr 16, 2018
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    Aug 13, 2015
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    6,656
    She's a beaut!

    One question. What do you mean by this:
    You need three things: compression, proper spark, and fuel. It sounds like you have compression and fuel. I'd start going backwards up the spark delivery and look inside the cap. It might have a crack. Do you have another cap and rotor you could try?

    With equal compression numbers, it sounds like all of the valves are opening and closing properly.

    What is the plug wet with? Gas or oil? Or.... antifreeze?
     
  10. Apr 16, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Not for me. Which site are you using to host your pictures? I'm blocking outlook live and facebook as trackers. All other content is supposed to be going through.
     
  11. Apr 16, 2018
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    Nope - not here. FWIW I am on a PC running Chrome. Glad you figured it out though...
     
  12. Apr 16, 2018
    stain

    stain New Member

    vt
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    By fire I mean spark. Got it figured. I am a auto tech by trade of over 29 years. Was looking for maybe some oddball situation that may be inherent to these 225's.
    I have been copying and pasting my pictures from my email.....
    How else can I post pictures? Everytime I try to upload the file is says it is too large
     
  13. Apr 16, 2018
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    Sorry, I didn't mean to talk down to you; you never know how much mechanical background people have. (y)

    The only thing odd about these engines is how they run. At idle they sound like potato-potato-potato....
     
  14. Apr 16, 2018
    stain

    stain New Member

    vt
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    No offense taken. This seems like a great site with many helpful people. We all need help from time to time no matter how long we have been doing this.
    I have yet to hear it run properly yet.
    I am guessing the carb settings are all wrong seeing as they were set for 5 cylinders. Any good starting point for the adjustment screws? I usually start with them at 1.5 turns, these are at 2.0 and 4.0 currently.
    Also the clutch slips but there is absolutely no free play in the pedal, like it never fully engages. I am hoping the same person adjusted the clutch linkage that installed the intake gaskets
     
  15. Apr 16, 2018
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    Jul 30, 2003
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    be careful what you wish for...

    1.5 turns out is a good starting point for idle mixture adjustment.
     
    Daryl likes this.
  16. Apr 19, 2018
    stain

    stain New Member

    vt
    Joined:
    Mar 4, 2018
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    She runs a whole lot better now. Got my new gaskets in and turned the idle screws to 1.5. It idles like a champ. It stumbles a bit on sudden throttle inputs. Still haven't gotten it up to 55 yet--no registration, but with some fine tuning and fresh gas it seems like it will be a runner.
    I also adjusted my clutch rods---no more slip!!!
     
    ITLKSEZ likes this.
  17. Apr 25, 2018
    commanlerwrangdo

    commanlerwrangdo Member

    Cleveland, Ohio
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    Feb 10, 2014
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    Welcome to the fun of Commandos. Brought my 67 out of the garage two Sundays ago. The accelerator pump in the carb has been an issue on this Jeep. The cheap Chinese pumps come apart and jam up the throttle to only 1/3 total opening. Ran the rig last summer with no accel pump once I figured out that if the engine is fully warm, it can drive without it and sure saves on petrol use!

    I just cleaned the ballast resistor terminals on it the other night and seemed like the power improved. Once it warmed fully up, it seemed like it was idling rich and lopey though. Figured I might have had it adjusted on the rich side due to no accel pump. Anyway, I grabbed the carb adjust tool and ending up leaning the mix 1 and 3/4 turns in on the right screw and 1 and 1/4 turns in on the left. Idle got so high I had to turn down base idle. Now the engine is so quiet all you hear is the hole in the Y pipe and the rocker on the RH shaft that I still need to clean out. Fun part is the accel is still cool without any stumbles.:coffee:
     
  18. Apr 25, 2018
    Daryl

    Daryl Sponsor

    Bonney Lake, WA
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    I have never seen a 2g carb that doesn't stumble. There may be one out there though.
     
    sterlclan likes this.
  19. Apr 27, 2018
    commanlerwrangdo

    commanlerwrangdo Member

    Cleveland, Ohio
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    Feb 10, 2014
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    Yeah, stumble versus not is usually the norm. As long as my 67's Dauntless is at full operating temp I can accel without stumble. However I only have 1/3 throttle opening, a full bore WOT (if my internal linkage wasn't jambed up) would most likely stumble!

    Main issue appears to be the cheap aftermarket accelerator pumps out there. They literally fall apart.
     
  20. Apr 27, 2018
    Alan28

    Alan28 Well-Known Member 2022 Sponsor

    Châtillon en...
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    Oct 21, 2012
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    Welcome from France. The problem with these old Jeep is to be patient. It took me 3 years to have something starting and running perfectly.
    Every time I start the engine, and go, I am surprised to have such a beautiful music of cylinders. These Jeep are un-break-able but all must be in good condition. There is no surprise.
    I don't see your photos, you can load them from your hard disk in jpeg small size, around 200k is good. I load pictures one by one.
    There are other solutions but with calm this works.
    That's the lesson of the Jeep : don't go fast but never stops! (except for fuel). Enjoy.
     
    commanlerwrangdo likes this.
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