1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Keeps Getting Worse

Discussion in 'Intermediate CJ-5/6/7/8' started by Garrett Pirkey, Apr 5, 2021.

  1. Apr 5, 2021
    Garrett Pirkey

    Garrett Pirkey New Member

    East texas
    Joined:
    Jun 16, 2020
    Messages:
    46
    Quick recap...77 CJ5, transplanted 304 with T176 & Dana 300. Engine cuts out when accelerating, this started mainly happening after I was able to get it out of 2Low and into regular 2wd. Engine for the most part ran strong in 2Low. It doesn't smoke bad, maybe a little white/blue on first crank up, cranks/turns over like it should, rumbles and pops but nothing major.

    I took it to a Mechanic said that it was a faulty carburetor, replaced it and now he said saying that the motor needs to be rebuilt. He says there is so much slack in the timing chain and cam to distributor gear that it will never run right. I am bummed out, I don't have the cash right now to do anything and I am not sure I can get out of what I have into it.

    I am going to pick it up and take it to another mechanic for a second opinion. What do you guys think?

    If I do have to rebuild, should i stay with the 304 or I've read that the 360 is a better option?
     
  2. Apr 5, 2021
    ITLKSEZ

    ITLKSEZ Having an avatar identity crisis

    Post Falls, ID
    Joined:
    Aug 13, 2015
    Messages:
    5,452
    Good.

    Even if the slop in the timing assembly was what’s wrong, that doesn’t necessitate an entire rebuild.

    Either it’s starving for fuel, or there’s an ignition issue.
     
  3. Apr 5, 2021
    timgr

    timgr Eppur si muove. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,305
    I agree, a sudden change like that is gas or spark. It may need the timing chain replaced, but you usually worry about it jumping time (skipping teeth or breaking) when it gets really sloppy.

    Nothing wrong with the 304. I think it has plenty of power for that chassis. However, a 360 will give the most horsepower increase for the least investment. A 20% increase in displacement should give you about a 20% improvement in horsepower. Likely more because the 360 heads are better. There will be additional costs with the 360, including a new flywheel. The seller will probably want more in exchange for the 360, although the 304 is likely a more valuable core.

    Maybe you could try to do some of your own work? A compression check would be a good start.
     
  4. Apr 5, 2021
    montanacj

    montanacj Member

    Joined:
    Jul 11, 2012
    Messages:
    754
    A rebuild would typically be called for after failed compression or leak down test or obvious valve train issues etc. I would get a second opinion for sure.
     
  5. Apr 5, 2021
    earlswrench

    earlswrench Member

    Atlanta, GA
    Joined:
    Apr 14, 2009
    Messages:
    130
    This is going to sound very elementary, but -- if you haven't already -- replace the fuel filter, spark plugs, spark plug wires, distributor cap and rotor. Any of these could cause those symptoms and they are cheap.

    Also, make sure all your ground cables are on tight and rust free.

    This is all part of the old engineers' trick: if it runs on gas, make sure there is gas in the tank. If it runs on electricity, make sure it's plugged in.

    Come to think of it, is the gas clean? Are you sure there's not any water in it? Has it been sitting a while? Gas can go bad in 6 months or less.
     
  6. Apr 7, 2021
    TheBeav1955

    TheBeav1955 Member

    Wyoming, Mi
    Joined:
    Apr 14, 2004
    Messages:
    283
    You might also check the coil they go bad as well and can be affected by RPMs. Also remove the dist. cap and see how much slop you can feel that can give you an insight as the the dist. gear to camshaft gear lash. If that feels excessive pull the dist. and have a look at its gear
     
  7. Apr 7, 2021
    OzFin

    OzFin Vintage Jeep Guy

    Michigan
    Joined:
    Jul 16, 2007
    Messages:
    726
    All sound advice listed above.
    In addition, an inexpensive way to check the timing chain is to remove the distributer cap so you can see the rotor. Use a breaker bar and socket and turn the crank until you just see the rotor start to move. Stop and mark the crankshaft balancer with chalk and make a corresponding match line on the timing tab indicator. Now turn the crankshaft the opposite direction until you just barely see the rotor start to move, then stop. Make another mark matching the crank balancer to the previously made mark on the timing tab then determine how many degrees of crankshaft turned before the slack was taken out of the timing chain to cause the rotor to just start to move. Anything more than about 5 degrees is a worn timing chain.
    If you start with the crankshaft balancer timing mark aligned at zero on the indicator tab you may be able to determine degrees of rotation without making any chalk marks at all, just read directly off the timing tab marks.
     
    Ol Fogie likes this.
  8. Apr 8, 2021
    Garrett Pirkey

    Garrett Pirkey New Member

    East texas
    Joined:
    Jun 16, 2020
    Messages:
    46
    I picked up the Jeep today and It’s running better than it was. I drove it twice today, figuring out the throttle and not pushing it hard until rpms are up. Kinda struggles at lower rpms.

    I took some videos, one at each muffler, one in the engine bay, idling and reving it. The guy i am taking it to said he really thinks it sounds like it has a vacuum leak. Do any of you having vacuum line diagram for the 304?

    I don’t have a socket/extension long enough to check the crank shaft slop

    Does anyone hear something else I should
    Start searching?

    Thank you all for all your comments.


    https://photos.app.goo.gl/XisjWA1MuEGvTe229
     
  9. Apr 8, 2021
    73 cj5

    73 cj5 Not ready for the junkyard yet 2020 Sponsor

    Mississippi
    Joined:
    Jan 10, 2014
    Messages:
    1,571
    If you think there's a vacuum leak start with a spray bottle with water that way you don't cause a fire. On that stumble at lower rpm, you could check the accelerator pump adjustment. Take off the air cleaner and look down the throat of the carb and look for the fuel spray when moving the throttle. I'm guessing you have an MC2100/2150?

    Here's a 77 manual. 1977 Jeep Factory TSM &amp TSM's
     
  10. Apr 8, 2021
    ITLKSEZ

    ITLKSEZ Having an avatar identity crisis

    Post Falls, ID
    Joined:
    Aug 13, 2015
    Messages:
    5,452
    FWIW, I got a 2100 carb from Rockauto for my dump truck, and it runs like garbage. The accelerator pump doesn’t work right, and the jets feel like they are too small. It runs when I need it too, so I haven’t been motivated enough to tear into it yet, but it has the same symptoms you are describing. Just keep in mind that it could still just be your carburetor.
     

Share This Page

New Posts