Engine Engine Idles High (randomly) Without Gas Being Depressed

Discussion in 'SN95 4.6L Mustang Tech' started by TheHoff, Jan 5, 2014.

  1. about 3 weeks ago, i noticed that my '01 Gt Bullitt, will idle high (between 1500 and 2400 rpm) when being driven and coming to a stop. sometimes i can get it to idle normaly after reving the motor to about 5600 rpm (while stopped)
    I can't force to duplicate when i want, it seems to be random...

    Any ideas?
    has anyone else had this problem?

    How can i fix it?
  2. Please list all modifications that you've done to the car including any tuning. Also post whether or not you had the A/C running (including defroster). Does the car do this when it's warmed up, cold, or doesn't matter?
    trombonedemon likes this.
  3. K&N Ram air intake

    rest of the mods are for handling and weight reduction

    no tunes

    it will do it with or without the A/C Or defroster

    sometimes it will happen 3 or 4 miles from home, starting at 15mph for the first mile...

    or it will start after getting on the highway, miles away from home...

    there seems to be no consistancy with it... sometimes it will return to normal, and then start up again after crusing on the highway...

    at first i thought it was from excessive accelleration but then i tried it as a normal driver, keeping up with traffic, and it will do then also...
  4. Pull codes and see if you have any, specifically for the mass air meter.

    Also try "reclocking" your meter. If the pig tail is directly on-top of the meter then rotate it so that it's at say... 15* different from its current position.

    It's possible that you're getting some dirty air turbulence over the mass air element.
  5. what do you mean by "relocking"?

    how do you get dirty air over the element with a filter?

    Could it have been cleaned wrong? or not oiled properly?
  6. No. Any time you run a mass of air down a tube, it swirls. You get vertices in the air flow. Sometimes with CAIs or Ram air kits, you create a condition where there's a turbulent spot of air hitting the sensor element.

    Reclocking the meter means to rotate it. It'll put the sensor element in a different location. It's why you see so many OEM air meters with screens over the inlet.


    Other possibilities that come to mind:

    Dirty IAC or leaking gasket
    Intermittent signal loss to MAF

    Pulling codes my help to narrow it down.
  7. Will do.
    Don't have a code reader though :cry:
  8. Any auto parts store will pull codes for free.