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  1. 88 YJ runs like butt

    88 YJ with the 4.2L it runs rough if i smash the throttle it will sputter and die. it also has no power i already know the timing is off ive tried playing with it and can't seem to get anywhere with it. has brand new cap rotor (for 300cid ford) plugs wires and a new ignition control module oem i was told i need to replace the ignition control module to an aftermarket one like msd i just want the power i know it should have any help os great thanks im new to this

  2. #2
    Join Date
    Feb 2009
    Location
    Dayton Ohio Area
    Posts
    5,162
    Do a Compression test, check if your cat is clogged.
    Check your plug wire firing order.
    Get that timing corrected.
    Is your battery fully charged and bring charged effectively? Clean the terminals and grounds.
    Last edited by JPNinPA; 12-13-2016 at 10:02 PM.
    "Never look down on anybody unless you're helping him up" - Jesse Jackson

  3. #3

    Re: 88 YJ runs like butt

    The stock Carter carbs are junk, consider replacing with a Motorcraft 2100 or 2150.

  4. #4

    Re: 88 YJ runs like butt

    if they did all the ignition stuff, is it a stock carb? for sure, that could be the trouble but without setting the timing, its hard to say.

    do you have a vacuum gage? that is the easiest way to check the timing.
    no more jeeps at this time. next time it will be a cj with a v8

  5. #5

    Re: 88 YJ runs like butt

    It's an aftermarket carb with a stock ignition control module and I don't have a vacuum gauge but I do have a timing light and there's no cat to be clogged and just fixed my battery issues

  6. #6
    Join Date
    Apr 2013
    Location
    Staten Island n.y.
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    2,000

    Re: 88 YJ runs like butt

    Agree that a compression test should performed to determine the engines health .
    Also , test the intake manifold for intake leaks at the base gasket where the carb bolts up but more in particular where the intake bolts up to the cylinder head . In - line engines are known for intake leaks there . You can try to retorque the intake hold down fasteners to see if improvement is found which would indicate a possible worn gasket but at least loose gasket seal.
    it would be best to soak the fasteners with penetrating oil first and allow time to soak in before attempting to tighten . If any of the nuts and bolts are frozen , you can snap a fastener trying to torque them . I would like to suggest tuning in the idle mixture screws for highest vacuum reading and even setting for proper synchronization of the fuel / air mixture being drawn from each side of the carb to ensure the carburetor is feeding the engine well . Equal turns out from seated position is proper sync and steady vacuum reading is desirable.
    before tuning can be done however , vacuum leaks will have to be checked for and corrected or any tuning attempts of the carb will be fruitless . You will no doubt have to obtain a vacuum gauge . A good tachometer may be helpful as well to ensure the engine is idling at correct rpm for carb setting and timing. A vacuum tests readings will be your first concern .
    If your engine is idling poorly but dosen't stall until you accelerate , it may be an intake gasket seal problem . In short spurts , squirt penetrating oil where carb bolts on to intake and where intake bolts to cylinder head . If a leak exists , a short climb in rpm will be detected .
    also , fuel pressure should be checked to ensure proper fuel delivery.
    a fuel pump that won't keep the float bowl at a proper level will cause fuel starvation .
    a vacuum gauge will be helpful to check if proper fuel draw is being obtained from fuel tank and a volume test would need to be performed if fuel pump output is suspected to be poor . That just involves removing the line from the carb and filling a glass jar a measuring volume and time it takes to fill jar . Steady flow is most important for good pressure and delivery .
    It is also possible the carb float may be stuck . If it were stuck open , carb would be flooding . Overflow would be seen . If float were stuck closed and fuel just barely enters float bowl forcing past float needle , float bowl not being adequately filled and miss during acceleration ( and stalling ) may be due to low fuel pressure / volume . The carbs accelerator pump can't draw enough fuel if float chamber isn't full and can't push fuel through its passages to help accelerate engine .
    Before suspecting any carb problems or attempting adjustment , look for vacuum leaks first .
    then , once vacuum reading is satisfactory and stable , ignition timing and carb adjustment can be performed . No tuning can be done until the engines health is determined via compression test and vacuum reading tests are first performed . Hope this helps . Please post results when you can .
    if timing light reading is erratic , it could be worn timing chain which affects idle and acceleration due to late valve timing which effects engine vacuum , in addition to vacuum leaks .
    Check for timing chain wear . With engine off , carefully turn engine damper / harmonic balancer with a breaker bar and watch distributor rotor . If balancer moves and rotor delays to rotate until balancer is rotated conciderably , a worn timing chain is evident .
    Last edited by greg92jeepxj; 12-14-2016 at 10:19 AM. Reason: Errors , corrections and additions
    Never overlook the obvious . It's usually right in front of us

  7. #7
    Join Date
    Apr 2013
    Location
    Staten Island n.y.
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    Re: 88 YJ runs like butt

    In addition to engine compression , intake and vacuum , valve timing ( timing chain ) and fuel delivery ( fuel pump ) and ignition timing and carburetor adjustment as well as state of tune , carburetor condition may have to be considered .
    not just base plate gasket seal is to be checked , although important .
    with the accerator linkage return spring disconnected , can the throttle shaft be moved excessive indicating the throttle shaft bore is worn and excessive . That will cause major vacuum leaks .
    things like fuel filter condition should not be forgotten . Check for fuel leaks too.
    a dirty carb externally is unsightly but internally is most important .
    Clogged passages and ports are detrimental to carburetor performance .
    Fuel logged nitrile floats and leaking brass floats ( cracks and bad solder joints ) cause excessive rich mixture and flooding . Worn accelerator pump diaphragm and plunger seals hurt acceleration . external linkage such as choke linkage worn and out of adjustment are not helpful to performance . Out of adjustment accerator linkage causes miss on acceration just as worn accelerator pump plungers do . A bad float or out of adjustment fouls up operation .
    These are some of the things found with carburetor problems .
    It is important to note however before considering carburetor repair , rebuild or replace that the previously posted checks pertains to the engine be checked and performed before placing blame and emphasis on the carburetor . The carburetor should be the last item on the list until all other items are addressed first . Although carburetors are blamed often and do develop faults , the engines health must first be determined or a good carb on a bad engine won't help .
    Last edited by greg92jeepxj; 12-14-2016 at 10:30 AM. Reason: Errors and additions
    Never overlook the obvious . It's usually right in front of us

  8. #8
    Join Date
    Feb 2009
    Location
    Dayton Ohio Area
    Posts
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    What battery issue did you fix? It is common for bad connections and poor grounds to wreak havoc on an engines performance. Just be sure all contacts are cleaned to a shine including ground at the engine and chassis. Sent from my iPhone using Jeepz.com mobile app
    Last edited by JPNinPA; 12-14-2016 at 07:02 PM.
    "Never look down on anybody unless you're helping him up" - Jesse Jackson

  9. #9

    Re: 88 YJ runs like butt

    you can add some extra grounds to help out. that carb could also cause trouble if its not the right size or set incorrectly. and, since its got an aftermarket carb, you can use the stock settings to get your timing close but to make it right, you need a vacuum gage
    no more jeeps at this time. next time it will be a cj with a v8

  10. #10

    Re: 88 YJ runs like butt

    I fixed terminals put a new battery and alternator in it i also sprayed gumout by the carb and intake it made the idle go low every once in a while but I couldn't find the leak

  11. #11
    Join Date
    Feb 2009
    Location
    Dayton Ohio Area
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    5,162
    Quote Originally Posted by livengood-88-YJ View Post
    I fixed terminals put a new battery and alternator in it i also sprayed gumout by the carb and intake it made the idle go low every once in a while but I couldn't find the leak
    Go slower with the carb cleaner and pin down the leak. It likely isn't visible. Cold be dry rotted connector, loose intake or bad gasket on the intake or at the carb.
    "Never look down on anybody unless you're helping him up" - Jesse Jackson

  12. #12

    Re: 88 YJ runs like butt

    update:
    i replaced some fuel lines and repaired a few vacuum leaks i found idles much better now. also removed the air filter to see if the choke was even working and the previous owner put one of the clips for the air filter in the opening on the carb to hold the choke wide open which explains why it fell on its face on hard accelerations so i took that out and it takes off fine except for around 50ish it has a small sputter which im guessing its timing still and ive never had an auto before but it seems like it should down shift on a hard acceleration but it doesnt and i looked for a kickdown cable and found nothing so any more advice on this ol girl would be awesome

  13. #13
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    Apr 2013
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    Staten Island n.y.
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    Re: 88 YJ runs like butt

    It's good to hear that you've made progress with repairs that have made such a difference toward improving the jeeps comdition. It was very wise to remove the clip you found in the throat of the carburetor . That wasn't a wise thing for the previous owner to do since there was a major risk of the clip falling into the engine and getting caught in an intake valve or worse .
    i believe the kick down for the torque flite trans on your jeep is supposed to be mechanical and not a cable . If there is no linkage from the trans up to the carburetor's accelerator linkage then it sounds like it's missing . I don't understand why it would have been removed but that now leaves you with the task of lactating a replacement . If I remember correctly , the kick down linkage worked more like a throttle valve to control line pressure on the torque flite trans .
    If that is the case , that may be why the engine is flattening out at that road speed since the engine is running at low rpm and there is a power loss .
    Ot seems that two areas need to be addressed now ; the choke linkage and the transmission's kick down / throttle valve linkage . The trans linkage fix for obvious reasons but the choke plate may not be staying in its proper position and your engine losing power due to not getting enough air into the engine . That may be the major reason for the loss of power and the miss .
    Never overlook the obvious . It's usually right in front of us

  14. #14

    Re: 88 YJ runs like butt

    the kick down or shift cintrol wouldn't be vacuum operated?

  15. #15
    Join Date
    Apr 2013
    Location
    Staten Island n.y.
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    Re: 88 YJ runs like butt

    Quote Originally Posted by livengood-88-YJ View Post
    the kick down or shift cintrol wouldn't be vacuum operated?
    I don't know if that trans has a vacuum operated shift modulater , which are normally fitted into the body of the trans , above the pan . They work with the valve body to control shifting .
    But the problem of down shifting is still the kick down / throttle valve , which I believe is a mechanical linkage next to the shift linkage . I think that is on the same shaft as the shift linkage . It then connects to the carburetor at the accelerator . Hope someone with a cj7 or YJ wrangler here can confirm that . But that's what I remember of a torque flite trans .
    Never overlook the obvious . It's usually right in front of us

  16. #16

    Re: 88 YJ runs like butt

    88 YJ runs like butt-20161216_120009.jpg
    heres a pic of my throttle linkage

  17. #17

    Re: 88 YJ runs like butt

    88 YJ runs like butt-20161216_120149.jpg

  18. #18

    Re: 88 YJ runs like butt

    you do need to make a kick down. your weber38 I missin the stuff to adapt over so the probably just manually set the trans to shift at a certain rpm. you can do that on the tf999.


    webers are very finicky on settings. fuel pressure and timing both will cause your hesitation issues
    no more jeeps at this time. next time it will be a cj with a v8

  19. #19

    Re: 88 YJ runs like butt

    that's a badass carb though. I would keep it
    no more jeeps at this time. next time it will be a cj with a v8

  20. #20

    Re: 88 YJ runs like butt

    so where can i get the stuff to switch it over?

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