1. Welcome to Jeeps.net!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Jeep discussion topics
    • Transfer over your build thread from a different forum to this one
    • Communicate privately with other Jeep owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Engine trouble

Discussion in 'Grand Cherokee' started by Jeep69, Feb 5, 2020.

  1. Feb 5, 2020 at 7:33 PM
    #1
    Jeep69

    Jeep69 [OP] New Member

    Joined:
    Feb 3, 2020
    Member:
    #4356
    Messages:
    3
    Gender:
    Male
    Vehicle:
    Blue 2003 grand cherekee
    None
    Any help. I have a03 Jeep Grand Cherokee with 4.0 straight 6 . we've changed Crank sensor 4 time's cam sensor . Tps sensor mass air sensor. All grounds were correct ohm's all power points read 5volts fuel pressure reads 60lb running 55 off Still runs rough hard start still throws no crank code. Any ideas
     
  2. Feb 5, 2020 at 8:45 PM
    #2
    Jim Beam

    Jim Beam Well-Known Member

    Joined:
    Feb 11, 2019
    Member:
    #2891
    Messages:
    596
    Gender:
    Male
    First Name:
    Donald
    Vehicle:
    1986 CJ7
    Fuel Injection, Dana 44s, T18, 4.10s w/lockers
    If you are not using a oem type cps, I would suggest changing out to one. For starters anyway. To make sure your computer has a good ground, run a wire from the computer housing to the battery negative.
     
    aggrex and Billy1234 like this.
  3. Feb 6, 2020 at 6:11 AM
    #3
    aggrex

    aggrex Well-Known Member

    Joined:
    Sep 12, 2016
    Member:
    #203
    Messages:
    4,831
    DE
    Vehicle:
    Backcountry '16
    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    I've joined a new underground membership that states a good ground is equally important as a good positive.

    IMG_20181119_163237.jpg
     
  4. Feb 6, 2020 at 9:45 AM
    #4
    Jeep69

    Jeep69 [OP] New Member

    Joined:
    Feb 3, 2020
    Member:
    #4356
    Messages:
    3
    Gender:
    Male
    Vehicle:
    Blue 2003 grand cherekee
    None
    We have checked all ground's cleaned them put back.check ohm's resistance all are within range .I have thought about putting a ground from battery to comp. What about dirty fly wheel.
     
  5. Feb 6, 2020 at 4:59 PM
    #5
    Jim Beam

    Jim Beam Well-Known Member

    Joined:
    Feb 11, 2019
    Member:
    #2891
    Messages:
    596
    Gender:
    Male
    First Name:
    Donald
    Vehicle:
    1986 CJ7
    Fuel Injection, Dana 44s, T18, 4.10s w/lockers
    A lot of starts can have an effect on a flywheel, metal chips can collect on the cps magnet and cause problems. There is a kit that routes the cps to the front vibration dampner. You did say that it has been replaced so it should be clean. I had a bad cps on a 4.0 Grand once and it did not throw a code either, I have heard similar stories. A bad cps will cause a 4.0 to stall and eventually not be able to restart.
     
    Jeep69[OP] likes this.
  6. Feb 6, 2020 at 5:09 PM
    #6
    Jeep69

    Jeep69 [OP] New Member

    Joined:
    Feb 3, 2020
    Member:
    #4356
    Messages:
    3
    Gender:
    Male
    Vehicle:
    Blue 2003 grand cherekee
    None
    Yes but we've replaced that sensor 4times now.
     
To Top