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Fixed: V6 Cutting out at cruising speeds?

Discussion in 'Early CJ5 and CJ6 Tech' started by sparky, May 14, 2006.

Page 7 of 50
  1. May 27, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    Re: V6 Cutting out at cruising speeds?

    :iagree:
     
    jpflat2a, May 27, 2006
    #121
  2. May 27, 2006
    Steamer

    Steamer Thick and gritty!

    SW OR
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    Re: V6 Cutting out at cruising speeds?

    Definitely watching this thread, Master!
     
    Steamer, May 27, 2006
    #122
  3. May 27, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    Ok, so I think the compression check was a fluke. I checked #6 again, 125 lbs. Checked it again, 125 lbs. again.

    Retarded the timing to 10* after, had more pep in 1 and 2. Still cuts out in 3.

    Put vacuum gauge on it at idle. Needle bounced erratically, that suggests timing or carb tuning. So I feel a bit better. That means I still have a healthy engine at least. Compression seems good...

    Maybe more tomorrow.
     
    sparky, May 27, 2006
    #123
  4. May 27, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
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    Re: V6 Cutting out at cruising speeds?

    if you rev it up to 2500-3000 RPM and hold it, whats the vac reading ?

    also, what was the reading at idle ?
     
    jpflat2a, May 27, 2006
    #124
  5. May 27, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    Reading at idle was around 15 but bounced. At 2000 RPM it was 20 inches IIRC, steady, I remember that.
     
    sparky, May 27, 2006
    #125
  6. May 27, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
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    Re: V6 Cutting out at cruising speeds?

    :?
    not too bad
    I'd like to see the idle reading higher...
    hmm...
     
    jpflat2a, May 27, 2006
    #126
  7. May 27, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    I almost said 24 inches, I can't really remember, just that it was steady at 2000 RPM and not at idle.
     
    sparky, May 27, 2006
    #127
  8. May 28, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
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    Re: V6 Cutting out at cruising speeds?

    just re-read the whole thread again, page by page
    fuel or electrical ?????
    the million $ question..
    you haven't really changed anything with all of the work you have performed and/or small things that you have discovered...
    same problem, falls on it's face when shifted into 3rd gear...
    not changing a thing is what has me baffled
    it's like we're looking in the wrong place ....
    but where else to look ?
    what is happening at or near 2500 rpm ?
    {thinking cap on}
     
    jpflat2a, May 28, 2006
    #128
  9. May 28, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    Neighbor is stumped too. He's an old shade tree mechanic with a '58 Chevy truck. He didn't believe me until I took him for a ride that it was only in 3rd gear. Started at 2200 RPM up to 2500 RPM tonite, but I drove at 4200 RPM in 2 at 55-60 mph for a bit just to convince myself...
     
    sparky, May 28, 2006
    #129
  10. May 28, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
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    Re: V6 Cutting out at cruising speeds?

    what air cleaner is on the engine ? stock dry type ?
    I'd almost suggest leaving the air cleaner assy off (at least the top) and go drive it
     
    jpflat2a, May 28, 2006
    #130
  11. May 28, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    Standard open element Fram air filter.

    I've got a CA emissions oil bath in the shed.
     
    sparky, May 28, 2006
    #131
  12. May 28, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    Re: V6 Cutting out at cruising speeds?

    'nuff for tonight.........
     
    jpflat2a, May 28, 2006
    #132
  13. May 28, 2006
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Re: V6 Cutting out at cruising speeds?

    Have you tried driving it as slow as possible in 3rd? I mean truly as slow as possible, then give it gas and see how it responds? Not flooring it but enough to make it steadily pick up speed till it starts cutting out. It seems as though you don't have a bad valve like you thought, but the valve springs haven't really been ruled out.
     
    Glenn, May 28, 2006
    #133
  14. May 28, 2006
    dohc281

    dohc281 It is what it is.

    Laurel Springs, N.J.
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    Re: V6 Cutting out at cruising speeds?

    It sounds like an ignition/distributor problem to me.
     
    dohc281, May 28, 2006
    #134
  15. May 28, 2006
    Toolmaker

    Toolmaker Member

    Westminster, SC
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    Re: V6 Cutting out at cruising speeds?

    You've tried different distributors with the same results, any chance you have a different carb you could try? I know you said yours is rebuilt, but if you could try another one maybe you could rule out one more thing.
     
    Toolmaker, May 28, 2006
    #135
  16. May 28, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    Glenn, doesn't matter if I floor it or ease into it from low speed or put it in 3 at a high speed, I had it at 60 mph in 2 last nite. Dropped in 3 and started sputtering. Went 1 to 3 and accelerated up slowly, sputters. Floor it, sputters.

    DOHC, it's done this with 2 distributors if you read the thread.

    Toolmaker, I don't have another carb to try. When I rebuilt it, it really didn't need it from what I saw.
     
    sparky, May 28, 2006
    #136
  17. May 28, 2006
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    Re: V6 Cutting out at cruising speeds?

    I know the poly tank is new.....probably the fuel lines as well......
    any chance, one is pinched somewhere ?
    between the tank and the frame ?
    a hose clamp that's loose ?
    is the carb being fed with the correct fuel outlet/pickup and not the return line ?
    I'd almost suggest rigging up another fuel tank/can and go drive it
     
    jpflat2a, May 28, 2006
    #137
  18. May 28, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    Thought about fuel delivery. Now you've got me wondering Jim. If I disconnected the lines from the fuel pump when I took the timing cover off the last time and hooked 'em up backwards? Hmmm.

    Gosh, I can't tell you how much I'd love for that to be it. The tank's new, the lines are new, or steel. I'll check that stuff though!
     
    sparky, May 28, 2006
    #138
  19. May 28, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
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    Re: V6 Cutting out at cruising speeds?

    No way with the way my pump is set up, well there is a way, but I didn't do it, to hook up the return to the carb.

    I'll be checking hose clamps, pinched lines, etc. after the auction today.

    I've been trying to figure out, I didn't do anything other than put a new distributor drive gear on. Didn't touch the timing chain, that would affect all gears though.

    It ran good with an EF distributor with no advance. But poorly with the distributor(s) made for it with mechanical and vacuum advance.

    Is there something about the jetting of the carb? Was it getting enough fuel with the wrong distributor and not enough with the right one now? I honestly know little about jetting, just what I've been able to read here and reading and doing are two very different things so my understanding is minimal at best.
     
    sparky, May 28, 2006
    #139
  20. May 28, 2006
    jhuey

    jhuey Michigan Jeeper!

    Indian River...
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    Re: V6 Cutting out at cruising speeds?

    I've been watching this thread, and there has been a lot of great input. When I get in the situation where I feel I'm just banging my head off the wall I start over. I go back to basics. I know it sounds counter productive, but something is being missed, and sometimes it is a simple thing. All right, The known:
    Engine seems healthy, good compression, vacuum ok , timing ok, no major problems there.
    Fuel supply fresh and unrestrictive, good pressure. Carb clean and adjusted properly, jetted as before problem arose.
    Electrical, distributer sound, all connections tight, all high tension wires good.
    I get the feeling this is going nowhere:(.
    First inclination I have is it's a fuel issue. It just sounds like it to me. I would eliminate fuel supply as you did with the swapping of distributers, on boats we bring an outside fuel tank into play, to do that, just a 6 gal boat tank, plumb it straight to the fuel pump keep the primer bulb handy, good job for a copilot, as you run along in 3rd if the problem comes back pump the primer bulb and observe. If problem is still there check the whole fuel system off up to the carb. You will have to look somewhere else. What is really intriguing for me and frustrating for you is when problem manifests. If it is not fuel than the ignition is cutting out, but the funny thing about that it is only in high gear and above 2500 rpm, with the engine speed being able to go above 2500 in second eliminates allot of things. Wind, vibration, linkage position, these things are different, the only thing (and I am reaching) is a wire is grounding out or a ground strap is loose. Again on boats we eliminate the wiring harness and hot wire the coil, and we ensure the ground path is ok. The other thing that come to mind is timing curve in distributer, but why would both distributers do the same thing. I guess a valve could be floating, but I would think it would show up at other times too. As I said earlier, the basics, compression, fuel, spark and when that stuff happens it's one of those. Sorry if I wasn't much help, wish I was there to help, not to say my magic wand is any better than anyone else's but I would enjoy a :stout: with you during the process!
    Joe
     
    jhuey, May 28, 2006
    #140
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