Results 1 to 12 of 12

Thread: High Idle - '86S

  1. #1
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    High Idle - '86S

    Just starting to open the shop manual now. Thought I'd check in to see if anyone can give me a place to start.

    Car RPMs high at idle / out of gear. Seems "normal" when I put into gear / shift. Can't determine exact RPMs since my gauge works intermittently. No apparent problems with throttle / cable.

    Can anyone let me know where to start looking?

    Thanks!

  2. #2
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    Going to see if I can pull any codes. As I recall, turn keys back and forth twice and leave in forward position the third time / check power loss light blinks?

  3. #3
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    Pulled codes 15, 23, 55.

    Don't have code book but I think one of these is for the speed control sensor which I haven't changed yet. I think 55 is the "end of cycle" code. Not sure what 23 is. I had a speed control sensor code which I thought went away when I swapped speed sensors but again, I'll need to search what Code 23 is. Checked codes twice and came up with same numbers.

  4. #4
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    OK...found the thread with the codes explained. As I've had 15, 23 for some time with no idle issues, I'm guessing I have an AIS motor issue. Any tips on how to check / replace is welcome.

  5. #5
    Hybrid booster
    Join Date
    Dec 2007
    Location
    Moon Township, PA
    Posts
    403

    Re: High Idle - '86S

    That could be an array of things. vacuum leak, throttle body gasket leak, maybe a brake booster leak, AIS motor, could be a map sensor, could be a logic module.

    I had a similiar problem, with the same code on my 84 Turbo Z. replaced some parts (Entire Throttle Body with alternate AIS motor and TPS and new TB gasket) but still have intermittant problems with it. Sometimes it idles low and other's it idles high. Next thing I'm gonna try is the MAP sensor. I've searched for vacuum leaks...but it's never being a problem when I have the time to troubleshoot. It's always running smooth when I am able to check it. No problems identifiable.

    When it idles fast, I can usually bring it down by pressing on the brake pedal pretty firmly. This kinda leads me to think it might be the brake booster, but it would act up all the time.

    HEY>.. just remembered. On my T2 GLHT, it idled fast once. It turned out, the vacuum cap on the brake booster came off somehow. That caused it to idle high all the time. Check and make sure it's in place. It's the small cylinder looking manifold which protrudes out of the booster. I think one nipple is capped, one leads to the heater control, and the other to the TB or intake manifold.

    I think that code declares nothing more than inconsistent voltage supply to the AIS motor, if memory serves me today.

  6. #6
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    Thanks, I'll check it out the vacuum cap and spray the AIS motor with silicone spray. Perhaps the pinter is stuck.

  7. #7
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    In a RARE stroke of genius I decided to crack the manual first before spraying down the AIS motor with silicone. First thing it mentioned was to check hoses, lines etc.

    Found the hose off the side of the intake and right where it "Ts" off, I found the black plastic piece at end of the hose "disconnected." I say disconnected because someone had tried to use plastic electrical tape to keep it together. While both ends fit neatly together, they don't snap into place.

    I couldn't find the hose in my '86 shop manual and will keep it taped together until someone can tell me what it is and how it's supposed to connect.

    Good news is idle is fine and my Power Loss light is off!!!!

    Here's a pic of the hose I'm having trouble with:


  8. #8
    The moderately moderate moderator Turbo Mopar Staff
    Join Date
    Dec 2006
    Location
    Akron, Ohio
    Posts
    6,870

    Re: High Idle - '86S

    That is a check valve.
    Bryan
    86 GLHS #161, 2016 Impala
    SDAC National Member, SDAC Buckeye Chapter Member

    A man has got to know his limitations.....

  9. #9
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    Does anyone know how the valve / orifice was originally connected? There is a male / female end. As mentioned, they mate fine but I didn't see a clip or retainer that held the two ends together.

    Used friction tape to keep it together for now but I couldn't find it in the '86 shop manual. Anyone have a PN for the hose/ orifice?

    Still idling fine.

  10. #10
    Hybrid booster
    Join Date
    Dec 2007
    Location
    Moon Township, PA
    Posts
    403

    Re: High Idle - '86S

    I'm glad you found your problem so easily. Problems like that can take days to troubleshoot, to no avail...

  11. #11

    Re: High Idle - '86S

    check valve: 4306 923

    restrictor: 4307 334

  12. #12
    Hybrid booster
    Join Date
    Jun 2008
    Location
    Detroit
    Posts
    392

    Re: High Idle - '86S

    Thanks!

Similar Threads

  1. High idle won't go back down...
    By 85shelbycharger in forum "I need help!"
    Replies: 12
    Last Post: 05-18-2009, 10:43 PM
  2. having high idle issues
    By TurboII in forum "I need help!"
    Replies: 5
    Last Post: 04-21-2009, 07:11 PM
  3. having high idle issues
    By TurboII in forum "I need help!"
    Replies: 0
    Last Post: 04-18-2009, 12:19 PM
  4. High Idle (~2000 RPM), bad AIS?
    By Shelbydaytona91 in forum "I need help!"
    Replies: 12
    Last Post: 08-29-2007, 04:24 PM
  5. High Idle..?
    By Wes85L in forum "I need help!"
    Replies: 9
    Last Post: 06-29-2006, 04:32 PM

Tags for this Thread

Posting Permissions

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