Idle Problems.. new thread for problems

Discussion in 'Fox 5.0 Mustang Tech' started by savegoodautonfg, Jul 31, 2007.

  1. 91foxbod50

    91foxbod50 Member

    Joined:
    Sep 26, 2007
    Messages:
    488
    Likes Received:
    0
    Trophy Points:
    16
    Im thinking more of the cts, I had that problem with my trans am. It tricked the computer into thinkin it was cold when it really was hot. I havent read all the reply's so i dont know exactly where your at.. but i'd pull it out and take a look at it anyways. you could possibly have a short in the wire somewhere or maybe a bad sensor
     
    #101
  2. jrichker

    jrichker StangNet's favorite TOOL
    SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,979
    Likes Received:
    425
    Trophy Points:
    134
    Location:
    Dublin GA
     
    #102
  3. savegoodautonfg

    savegoodautonfg New Member

    Joined:
    May 11, 2005
    Messages:
    1,085
    Likes Received:
    0
    Trophy Points:
    0
     
    #103
  4. savegoodautonfg

    savegoodautonfg New Member

    Joined:
    May 11, 2005
    Messages:
    1,085
    Likes Received:
    0
    Trophy Points:
    0
     
    #104
  5. jrichker

    jrichker StangNet's favorite TOOL
    SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,979
    Likes Received:
    425
    Trophy Points:
    134
    Location:
    Dublin GA
    It is the main EFI body wiring harness. See the digaram for what a typical 5.0 fox Mustang EFI body harness looks like. You will see that it connects to almost everything under the hood.

    Diagram courtesy of Tmoss & Stang&2birds
    [​IMG]

    See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

    Ignition switch wiring
    http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

    Fuel pump, alternator, ignition & A/C wiring
    http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

    Computer, actuator & sensor wiring
    http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

    Fuse panel layout
    http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

    Vacuum routing
    http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
     
    #105
  6. savegoodautonfg

    savegoodautonfg New Member

    Joined:
    May 11, 2005
    Messages:
    1,085
    Likes Received:
    0
    Trophy Points:
    0
    Jritcher, can you possibly circle on that diagram where exactly i have to check the wiring at?
     
    #106
  7. jrichker

    jrichker StangNet's favorite TOOL
    SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,979
    Likes Received:
    425
    Trophy Points:
    134
    Location:
    Dublin GA
    Split the harness open in the area of where connectors, 20,21 & 29 join the main harness. The splice for the black/white signal ground should be in that area.
     
    #107
  8. savegoodautonfg

    savegoodautonfg New Member

    Joined:
    May 11, 2005
    Messages:
    1,085
    Likes Received:
    0
    Trophy Points:
    0
    i let it stick today and popped my hood and disconnect TPS and idle went down and i reconnected it and it was'nt sticking after being reconnected.
     
    #108
  9. jrichker

    jrichker StangNet's favorite TOOL
    SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,979
    Likes Received:
    425
    Trophy Points:
    134
    Location:
    Dublin GA
    You have just given more proof of a TFI signal ground problem. Try using a DVM to check the TFI voltages next time it happens.
     
    #109
  10. ninety15.0

    ninety15.0 New Member

    Joined:
    Mar 11, 2004
    Messages:
    1,339
    Likes Received:
    0
    Trophy Points:
    0
    Dude...i checked in on this thread about a month ago. Jrichker is one patient man helping you out like this. this thread makes me wonder if you even look at the links he gives you. Its all right there...just read the stuff and fix the problem. There's only so many things it could possibly be! Those diagrams are awesome and very detailed....and in COLOR. shouldnt be that hard to follow his instructions and do some testing/diagnosis by yourself.

    You will never learn how to diagnose/fix car problems if you ask someone to hold you hand the whole time.
     
    #110
  11. baldy1

    baldy1 New Member

    Joined:
    May 6, 2005
    Messages:
    128
    Showcase:
    8
    Albums:
    1
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Portsmouth Va
    Have u pulled any codes yet. If you have what are they.Also the MAF the TB and the injectors have to match. That will confuse the computer. What lb injectors are you running.
     
    #111

Share This Page