Idle Speed

[MRundel]

My 01 (Job 2) idles fast. 1500-2000 rpm indicated. It does idle very smooth. No codes thrown. i've cleaned the MAF, throttle body and IAC. Ran Seafoam through the induction system. I've disconnected the battery and let it set to re-set the system. I checked the throttle adjustment screw, its backed out so that's not it.

I don't want to play the replace this game till its right but I'd sure like suggestions as to what to do next.

 

[MRundel]

52 views and no suggestions. Surely someone has had this problem and figured it out.

 

[swshawaii]

That's a throttle stop. Did you remove the throttle position sensor for any reason? Unlikely high idle cause, but is PCV elbow OK?

http://www.explorerforum.com/forums/showthread.php?t=314670

 

[MRundel]

Haven't checked the TPS. I inspected the PCV routing once but will check it again. I thought a PCV vacuum leak resulted in an engine fault code.

 

[swshawaii]

I thought a PCV vacuum leak resulted in an engine fault code.

Usually does. I've read more than once where the "elbow" was split on the bottom and didn't throw a CEL or lean codes.

 

[429CJ-3X2]

52 views and no suggestions. Surely someone has had this problem and figured it out.

Sounds like a vacuum leak to me, too, but I don't know enough to tell you where to look.

52 views represent a miniscule % of the members of this forum, and there are thousands of non-members viewing these threads who can't answer them because they aren't members. A lot of those viewers could be having the same problem. Better to wait for someone who knows what they are talking about to weigh in.

 

[MRundel]

The idle is fixed. I disconnected the IAC valve and there was no change. I pulled the valve and noted the piston was not fully seated. I pushed it into position, re-installed and left unplugged. Started the engine and it idled at factory spec. Plugged the IACV back up and the idle shot up and stayed there. Took the valve back off and found the piston not seated again.

Call to O'Reilly's and $70 later, problem solved. Idle is now around factory spec. The ST brakes better since I'm not fighting the engine.

Thanks to all that responded.

 

[01STrunner]

Good to know! Mines been idling low and this might help.

 

[theluke19]

Good to know! Mines been idling low and this might help.

same - I feel like after cranking that sometimes it may not stay running.. but it always does

 

[01STrunner]

same - I feel like after cranking that sometimes it may not stay running.. but it always does

That's exactly what mines doing. Hydro locking a few months ago didn't help...

 

[theluke19]

Got a new air filter - whatdya know, doesn't happen anymore.