Session time has been extended...

Instead of 30 minutes, you will be logged into for 1.5 hours of inactivity before being logged-out. Also instead of having only 30 minutes to edit a post, it has now been extended to 60 minutes.
See more
See less

Fluctuating Idle Problem

  • Filter
  • Time
  • Show
Clear All
new posts

  • Fluctuating Idle Problem

    Hi Everyone,
    My idle fluctuates between 800 - 1100rpm, this problem occurs when the car is at normal operating temp and is sitting idling. It will idle happily at the normal 800 - 900rpm, I then hear an increase in engine speed and see the revs have increased to approx 1100rpm. It will run at this speed for approx 45 seconds then drop back to the normal idle position and remain there for approx 45 seconds then jump back up to 1100rpm for 45 seconds then back down again. This cycle will repeat itself for as long as the car is idling.

    I have checked the usual two places on the throttle bodies and also the elbow on the air plenum, for air leaks. I have swapped the idle control valve and the air flow meter from a friends car, that runs fine, but no change.

    Any ideas ?

    Many thanks,

  • #2
    I just read something about that regarding the fpr. Here is the link


    • #3
      Originally posted by fspine
      I just read something about that regarding the fpr. Here is the link
      I have the same issue....mine even fluctuates back to lean occastionally why driving at very low throttle loads...

      Im replacing the FPR this week..hopefully it works


      • #4
        Doesn't a faulty 02 sensor cause a similar problem? I know mine went bad and the idle bounced around, but faster than 45sec loops...