98 TJ won’t run

Discussion in 'General Tech' started by Collin Crosby, Mar 25, 2020.

  1. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
    Hey y’all hope everyone is doing good with everything closing down.
    I got a problem and don’t know where to start I got a 98 TJ 4.0 that was dead last week so I figured I left something on and charged the battery. Battery held a charge and I drove it to work when I was ready to leave work it was dead again so I jumped it off and I figured the alternator was bad drove home and changed the alternator now it won’t run it will start good but no fire.

    I’ve replaced:
    Alternator
    Crank sensor
    Battery
    Spark plugs

    Ive check:
    Fuses and relays
    Grounds

    All I got is a test light and the ignition coil is not getting any power when the key is on and while starting

    I don’t what to do anymore everything looks fine I’m wondering if messed up the Ecu or something jumping it off or disconnecting the battery while it’s running any suggestions will be appreciated thank you.
     
    Last edited: Mar 25, 2020
  2. Drunktaco

    Drunktaco Active Member

    Joined:
    Mar 21, 2018
    Location:
    SWVA
    When you turn the key do the lights, radio, and everything else work it just won’t crank?

    I had that issue a while back on mine and behind the key cylinder is a square plastic rod that goes into the ignition switch, mine had broke/wallered the slot out and was slipping when I was trying to turn it over to start, when you pull it the key cylinder and stuff out, you’ll see a little square switch, stick a screwdriver or something in it and cycle it through the positions and see if it’ll start.
     
  3. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
    Yeah I looked it and it was moving when I turn the ignition but I don’t know if worked good enough it’s orange right
     
  4. Drunktaco

    Drunktaco Active Member

    Joined:
    Mar 21, 2018
    Location:
    SWVA
    That red circled piece is what’s usually broke. It goes into a square hole/switch that as the key turns it makes stuff turn on, engine start etc.
     

    Attached Files:

  5. Drunktaco

    Drunktaco Active Member

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    Mar 21, 2018
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    SWVA
    Any update man?
     
  6. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
    Okay and yours mm
    not yet do I gotta pull the steering wheel or take those special torx bits bolts out to get it off
     
  7. Drunktaco

    Drunktaco Active Member

    Joined:
    Mar 21, 2018
    Location:
    SWVA
    It’s been a bit but steering wheel stays on, Pry the key insert cover off and a couple of screws top and bottom on the cover and pull the cover off the steering column. There’s 3 maybe torx bolts holding the cylinder in. Take those out and everything should slide out. I’ll go do it and take some pics if you want. I can do it in probably 10 mins. Its not too bad, just pull stuff apart, there’s not much to put back together.

    Not sure what the “Okay and yours mm” is about but hell yeah either way lol
     
  8. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
    You don’t have to I gotta get those special torx bits with the hole in the middle to get it off everything closing early and wasn’t able to get them today and I was about to reply to your other post and notice you sent another one
     
  9. Drunktaco

    Drunktaco Active Member

    Joined:
    Mar 21, 2018
    Location:
    SWVA
    gotcha. It’s not too bad man. That’s probably the problem. The connection piece can be hard to find. I junk yarded mine and in the mean time I used a screw driver to start my Jeep lol eBay probably has them if that’s what it is.
     
  10. Collin Crosby

    Collin Crosby Member

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    Aug 21, 2015
    Location:
    High Point, NC
    Took it apart everything looks fine
     
  11. Drunktaco

    Drunktaco Active Member

    Joined:
    Mar 21, 2018
    Location:
    SWVA
    Did you stick a screwdriver or something in there and turn the switch over to see if that made it crank?

    you might’ve lost a wire/ground or something. What’s got you so hell bent on a new ecm out of curiosity? That could be it, but I’d hate to see you get a new one and it be something else.
     
  12. Collin Crosby

    Collin Crosby Member

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    Aug 21, 2015
    Location:
    High Point, NC
    No it starts but I can’t get any power to the distributor, ignition coil and cam sensor
     
  13. Drunktaco

    Drunktaco Active Member

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    Mar 21, 2018
    Location:
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    Alright, turn the key, it’s cranks just no juice to the coil/dis/plugs right?
     
  14. Collin Crosby

    Collin Crosby Member

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    Aug 21, 2015
    Location:
    High Point, NC
    I thought about putting a screw driver in there and turning it but I didn’t want to mess anything up in there
     
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  15. Collin Crosby

    Collin Crosby Member

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    Aug 21, 2015
    Location:
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    Yes
     
  16. Drunktaco

    Drunktaco Active Member

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    it’s a switch, it don’t take much and you’ll fee the positions in it, you won’t mess anything up.
     
  17. Drunktaco

    Drunktaco Active Member

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    Mar 21, 2018
    Location:
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    Switch is top left, that’s a wiring diagram. Idk if it’ll help you or not but it might give you an idea.
     

    Attached Files:

  18. Drunktaco

    Drunktaco Active Member

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    Mar 21, 2018
    Location:
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    If it cranks when you turn the key though, it won’t be the ignition switch I don’t think.
     
  19. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
    I took the switch off turned it with a flat head and it did the same thing
     
  20. 77GreenMachine

    77GreenMachine Phillip Talton

    Joined:
    Mar 30, 2010
    Location:
    Trinity, NC
    Do you have fuel pressure? There’s a schrader valve on the fuel rail, if you push it in fuel should squirt out.

    You can also try a little starter fluid, if it fires that will tell your that you have spark but no fuel.
     
  21. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
     
  22. Collin Crosby

    Collin Crosby Member

    Joined:
    Aug 21, 2015
    Location:
    High Point, NC
    Tried starter fluid want do anything
     
  23. Drunktaco

    Drunktaco Active Member

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    Mar 21, 2018
    Location:
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    When you first turn the key on the ASD (automatic shutdown) relay should close & send 12v power to the coil & injectors. After 2-3 seconds the ASD should open & kill power to the coil & injectors. When you turn the key to start & the engine starts cranking you should get the ASD closing & 12v power back to the coil & injectors if the PCM gets a signal from the crank position sensor.

    No signal, ASD stays open.

    Also when the PCM sees a crank signal it should start pulsing a ground signal to the coil & injectors & it should start.
    Check for each of these conditions & that’ll give you some kind of idea on what’s up.
     
  24. Drunktaco

    Drunktaco Active Member

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    Location:
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    Another diagram
     

    Attached Files:

  25. Collin Crosby

    Collin Crosby Member

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    Aug 21, 2015
    Location:
    High Point, NC
    I’m having a hard time understanding the diagram is the stuff at the bottom of the paper the pins on the connector to the pcm
     

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