Thread: WJ 4.7 fuel consumption went up and doesent want to start

Results 1 to 7 of 7
  1. #1 WJ 4.7 fuel consumption went up and doesent want to start 
    Junior Member
    Join Date
    Oct 2016
    Location
    Estonia
    Posts
    2
    Rep Power
    0
    Hi,

    Im having problems with my 4.7 WJ. When its cold, it takes about 3 seconds of cranking before it starts. It used to start under a second. Additionally, average fuel consumption went from 15.2 to 19.7 litres per 100km after the starting problems started.
    If I turn the ignition about 3 times, before starting it starts better.

    No codes come up when key is turned 3 times. Also took it to the dealership few days ago and ran diagnostics cpu. Again, no results.
    Where to look and what to replace?


    Thanks
    Reply With Quote  
     

  2. #2 Re: WJ 4.7 fuel consumption went up and doesent want to start 
    Senior Member Grand Slam West Planner Ted_Z's Avatar
    Join Date
    May 2007
    Location
    Denver, CO
    Posts
    1,096
    Rep Power
    80
    My first guess would be you might have a leaky injector.
    -Ted Z
    '97 Grand Cherokee Laredo w/ stuff
    '02 Grand Cherokee Limited w/ less stuff
    Quote Originally Posted by Cody View Post
    everytime someone makes a bumper with a stinger, God kills 6 baby Koala's.
    Reply With Quote  
     

  3. #3 Re: WJ 4.7 fuel consumption went up and doesent want to start 
    Junior Member
    Join Date
    Oct 2016
    Location
    Estonia
    Posts
    2
    Rep Power
    0
    Unfortunately I havent managed to discover any leaks. Inspected pipes form the tank to the engine. Everything is dry. Also the injector rails are dry.
    Reply With Quote  
     

  4. #4 Re: WJ 4.7 fuel consumption went up and doesent want to start 
    Senior Member Grand Slam West Planner Ted_Z's Avatar
    Join Date
    May 2007
    Location
    Denver, CO
    Posts
    1,096
    Rep Power
    80
    The injector wouldn't be shutting off all the way and leaking into the combustion chamber, not leaking externally.
    -Ted Z
    '97 Grand Cherokee Laredo w/ stuff
    '02 Grand Cherokee Limited w/ less stuff
    Quote Originally Posted by Cody View Post
    everytime someone makes a bumper with a stinger, God kills 6 baby Koala's.
    Reply With Quote  
     

  5. #5 Re: WJ 4.7 fuel consumption went up and doesent want to start 
    Member Tuzmaster's Avatar
    Join Date
    Dec 2016
    Location
    Colorado Springs
    Posts
    182
    Rep Power
    31
    Check to make sure your MAP or MAF sensors are in good condition. You would have one or the other but not both. pre 01 (I believe) you would have a MAP (Manifold Absolute Pressure) sensor. Post, you would have MAF (Mass Airflow Sensor). MAP sensor would be on the throttle body, while MAF on the intake hose somewhere.

    Get a cleaner of some sort and clean them out. If that does something, than whichever sensor you have is probably going bad.

    If you already figured it out, than ignore this post
    Reply With Quote  
     

  6. #6 Re: WJ 4.7 fuel consumption went up and doesent want to start 
    Senior Member Grand Slam West Planner K2's Avatar
    Join Date
    Jun 2004
    Posts
    964
    Rep Power
    98
    Thanks, I'm getting in the 10-11 mpg range. I'll try the maf cleaner.
    02 WJ, Lift, dents, noise and smoke.
    Reply With Quote  
     

  7. #7 Re: WJ 4.7 fuel consumption went up and doesent want to start 
    Junior Member
    Join Date
    Oct 2019
    Location
    Lexington, Kentucky
    Posts
    3
    Rep Power
    0
    I had the starting issue in my wj. My fuel gauge was out anyways so i decided to change fuel pumps. Fixed starting issue, may be something for you to look into!
    Reply With Quote  
     

Thread Information
Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •