Results 1 to 4 of 4

Thread: Cold rough idle issue.

  1. #1
    prerunner1982's Avatar
    prerunner1982 is offline Level: Uber Jeep Cherokee Trailer Queen
    Join Date
    Jun 2009
    Location
    Edmond, OK
    Posts
    5,013

    Default Cold rough idle issue.

    97 XJ with 4.0 and about 150K miles.

    Hard to start and once started you have to feather the throttle to keep it running. Once warmed up starts and idles fine. Let it cool and it's hard to start and keep running again.

    The IAC has been cleaned which allowed it to idle better when warm.
    Coil and distributor cap/rotor have been changed as well.

    We (Father and I) are thinking it may be fuel related. The previous owner replaced the fuel pump/sending unit and likely didn't get the seal on right as it will over flow from the top of the tank. Could this leak and lack of pressure in the tank have anything to do with the idle issue?

    Any other ideas?

    Thanks
    Last edited by prerunner1982; 03-23-2015 at 08:03 AM.
    1993 2 door 4x4 4.0 5 speed
    1997 4 door 4x2 4.0 auto RIP 6/6/2016
    2000 4 door 4x2 4.0 auto


    Day of Dirt Adventure

  2. #2
    Join Date
    Sep 2009
    Location
    Chico, CA
    Posts
    29,847

    Default Re: Cold rough idle issue.

    I think to answer that you need to check your fuel pressure. Got access to a gauge?
    230 hp 4.3L Chevy
    Built 4L60E with manual lockout
    Atlas 4 speed
    Griffin radiator
    On board air
    Warn 9.5ti on custom bumper
    7.5" RE front and bastard pack rear on custom long arms
    30 gal gas tank
    lockers
    And a bunch of other stuff

  3. #3
    prerunner1982's Avatar
    prerunner1982 is offline Level: Uber Jeep Cherokee Trailer Queen
    Join Date
    Jun 2009
    Location
    Edmond, OK
    Posts
    5,013

    Default Re: Cold rough idle issue.

    Yes and that was likely going to be our next step, but wanted to see what others thought as well.
    1993 2 door 4x4 4.0 5 speed
    1997 4 door 4x2 4.0 auto RIP 6/6/2016
    2000 4 door 4x2 4.0 auto


    Day of Dirt Adventure

  4. #4
    Join Date
    Mar 2009
    Location
    Katy, Texas
    Posts
    27,332

    Default Re: Cold rough idle issue.

    My fuel pressure would drop to almost zero about 15 seconds after I turned off the engine. On first start up it would run rough for about 30 seconds, maybe. I replaced the submerged fuel assembly and all the problems went away.

Similar Threads

  1. Rough Idle ....
    By Oddball684 in forum General Talk
    Replies: 8
    Last Post: 10-14-2014, 09:40 PM
  2. Random Rough Idle - CEL suggests TPS Voltage Issue
    By JargonXJ in forum OEM/Factory
    Replies: 3
    Last Post: 07-13-2014, 10:58 AM
  3. No cure for Rough idle..
    By SeniorGustas in forum General Talk
    Replies: 14
    Last Post: 05-05-2013, 12:22 PM
  4. I have a rough idle, what can I do to fix it?
    By islandbum in forum OEM/Factory
    Replies: 4
    Last Post: 05-03-2011, 08:13 PM
  5. Rough idle
    By greenchevy in forum OEM/Factory
    Replies: 20
    Last Post: 03-29-2011, 08:23 AM

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

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