high idle on warm start ?

[rideflhr]

Hi, I have been experiencing a problem the last couple weeks that I could use some help with . It's intermitent ,so no way can I take it to the dealer and expect them to fix it .
  this has happened about 5 times . when I start a warmed up bike it will idle at 1500-to 1700 rpm . If I shut down and try again ,all is good . Any brilliant ideas ?  I used to be in the auto repair business  awhile ago and people could never get their cars to screw up at my shop.  I probably should have kept my perfectly good CARBURATED Road King .
2012 Deluxe, 4500 mi. Vxied, Rush 1.75", Big Sucker and very shiny .
                   JIM

[rbabos]

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

[rideflhr]

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

  Ok, What the hell is an "IAC" motor .If hung -up , can I un-hang it ?

[harleyjt]

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

  Ok, What the hell is an "IAC" motor .If hung -up , can I un-hang it ?

IAC = Idle Air Control motor.   Usually a stepper type motor that regulates air thru the idle control circuit in the throttle body.  Gives more precise control of the air than moving the throttle blade.  May be a software glitch. i would let the dealer at least look at it.  Sometimes they know things from experience that we don't.  They can also follow their tech help process to see if its a known issue.  I agree - intermittants are the worst thing in the world to fix.  You usually can't fix something when it ain't broke.
jt

[BAKON]

Take air cleaner off and look inside. Should see a small plunger move up then down when you turn ignition on and switch set to run. Dont need to hit starter button. Will move at same time you hear fuel pump. Spray it with carb cleaner. Might be sticking or gunked up from oil blow back from head breather.

[BAKON]

Or intake leak. Spray cleaner around intake seals and see if idle changes.

[rideflhr]

Thnx , all good advice . Will try what I  can .
                   JIM

[rideflhr]

Thnx , all good advice . Will try what I  can .
                   JIM

  Well I put my stock plugs in and rode the Cherohala Skyway . I stopped at lots of overlooks ,carefully let the idle settle down and used the ignition switch rather than kill switch as usual . No problemo. So, maybe its OK . Who Knows .
   I do miss my carb . The whole thing with bikes is supposed to be basic, simple transportation . Now they have as many gadgets
 as some cars .Any of which will eventually screw up . I had six kickstart bikes . I never ,ever, ever couldnt get one to fire . It was a bitch sometimes . I always carried extra plugs, but they always started . It also kept the girls and sissies off the road .
   Thanx for the help .
                                       JIM

[Ken R]

 

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

On a 2012 with throttle by wire?    I thought the stepper motors went away in 2009.   
 
My 2010 Limited sometimes idles up to 1,400 to 1,500 rpm on warm start-up.  Not every time, quite intermittent.  Sounds like the same that you experience.  If I just let it idle for 5 -10 seconds, it settles right down.  Seems like a long wait, but really isn't.

[rbabos]

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

On a 2012 with throttle by wire?    I thought the stepper motors went away in 2009.   
 
My 2010 Limited sometimes idles up to 1,400 to 1,500 rpm on warm start-up.  Not every time, quite intermittent.  Sounds like the same that you experience.  If I just let it idle for 5 -10 seconds, it settles right down.  Seems like a long wait, but really isn't.

True. I missed that. Still needs a home postion on the blade then.
Ron

[rideflhr]

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

On a 2012 with throttle by wire?    I thought the stepper motors went away in 2009.   
 
My 2010 Limited sometimes idles up to 1,400 to 1,500 rpm on warm start-up.  Not every time, quite intermittent.  Sounds like the same that you experience.  If I just let it idle for 5 -10 seconds, it settles right down.  Seems like a long wait, but really isn't.

True. I missed that. Still needs a home postion on the blade then.
Ron
[/quote
Hi, It's not TBW on a softail . I dont think it would go down to normal on its own . I dont have a lot of patience with stuff not doing its job correctly , so I probably never waited . Will try that on the next occurance . Last time it malfuntioned I started and rode off quickly . I had to stop and restart.

[Ken R]

With an ignition recycle fixing it , most likely the iac motor is not following the correct steps (home postion). Sounds like it' hanging up.
Ron

On a 2012 with throttle by wire?    I thought the stepper motors went away in 2009.   
 
My 2010 Limited sometimes idles up to 1,400 to 1,500 rpm on warm start-up.  Not every time, quite intermittent.  Sounds like the same that you experience.  If I just let it idle for 5 -10 seconds, it settles right down.  Seems like a long wait, but really isn't.

True. I missed that. Still needs a home postion on the blade then.
Ron

Well, the OP says not TBW on a SoftTail in 2012.  I guess I was wrong about 2009+ all being TBW. 
 
It's incredible how precise the electronic throttle is.  The idle speed needs extremely precise control.  Slightly press open or slightly press the butterfly in the close direction and the idle RPM varies greatly.  Only takes thousandths of an inch to make a large idle speed differences. 

[FLTRI]

Try cleaning the IAC port or replace it since it is what controls rpm.
Air leaks can cause hang-up but it should repeat.
Bob

[rbabos]

 The ECM controls the idle. Based on temp sensor, idle numbers in the calibration . IAC is the device the ecm uses to set the rpm.  It can be a faulty iac, intake leak of some form, bad head temp sensor to cause higher than normal idle. Does it appear to go into cold start, as in will the idle eventually drop on its own after running a bit?  Not sure if recycling the switch will alter idle if it's a faulty temp sensor. Same with intake leak. It will remain. Speed sensor goes the other direction, so it's not that.
IAC  is cheap enough. If cleaning won't do it, most likely won't if it's hanging open , then replace it.
Ron