Throttle idle problem (Newbie)

[DesertHog]

Hi all; I've encountered a throttle problem with my '08 XL1200C. After riding for 45mins or so, or until the engine is hot, the engine won't return to idle on closing the throttle. The throttle grip itself snaps closed OK but the motor continues to run at high revs. Once I get stopped, say at traffic signals, after 30-45 seconds the idle speed will reduce to normal. Also if I hit the kill switch and then immediately re-start, the engine will re-start at normal idle revs.
I've tried adjusting the throttle cable adjusters, which seems to help a little, but because the problem can't be replicated at a standstill it's proving a real PITA to sort. Dealership can't find a fault code anywhere either.
Any advice or suggestions would be most welcome.

[FoxsterUK]

I understand this to be fairly common on some EFI Sportsters. Do a search using the Google search at the bottom of the page and you should find other posts on this.

[jharback]

Originally Posted by FoxsterUK

I understand this to be fairly common on some EFI Sportsters. Do a search using the Google search at the bottom of the page and you should find other posts on this.

Have you tried using the Google search function lately. You get everything but, what your looking for. Boolean operators don't work so you end up getting everything. Might as well page thru the appropriate forum.

[DesertHog]

Originally Posted by FoxsterUK

I understand this to be fairly common on some EFI Sportsters. Do a search using the Google search at the bottom of the page and you should find other posts on this.

I did search this and other forums before posting and found a number of threads relating to throttle and cable adjustments on carbed models, but nothing related to these symptoms. Will keep looking. Thanks for the reply.

[Bob F]

Video the problem to document it. The dealer should be able to duplicate the problem with a test ride. If all else fails, Harley Davidson Customer Service 414-343-4056.

[Baphomet]

Originally Posted by DesertHog

Hi all; I've encountered a throttle problem with my '08 XL1200C. After riding for 45mins or so, or until the engine is hot, the engine won't return to idle on closing the throttle. The throttle grip itself snaps closed OK but the motor continues to run at high revs. Once I get stopped, say at traffic signals, after 30-45 seconds the idle speed will reduce to normal. Also if I hit the kill switch and then immediately re-start, the engine will re-start at normal idle revs.
I've tried adjusting the throttle cable adjusters, which seems to help a little, but because the problem can't be replicated at a standstill it's proving a real PITA to sort. Dealership can't find a fault code anywhere either.
Any advice or suggestions would be most welcome.

On another forum I frequent a guy has an 08 Ultra that did the high idle thing and said he did a reset with the ignition (cycle on off 4 times then start) and the idle was no problem after that.

I am not suggesting that this will solve your issue, but it does point to a glitch in the ECM software which there might be a fix for by now. Perhaps your dealership doesn't keep on top of tech bulletins, or maybe there isn't a tech bulletin. In either case, since the problem doesn't seem to be mechanical I would go on the assumption that it is ECM related.

[Bone]

Originally Posted by FoxsterUK

I understand this to be fairly common on some EFI Sportsters. Do a search using the Google search at the bottom of the page and you should find other posts on this.

Not really, MOST idle complaints on EFI bikes (stumbling or running a bit high) has to do with cold startup.

This might be the first I've heard that is definitely when the motor is fully warmed.

My guess?

IF shutting it down and restarting didn't fix it I would say it COULD possibly be mechanical (say a vacuum leak that becomes more pronounced when it heats up to a certain point).

BUT because shutting it down and restarting makes it go away it's electrical.

Either a problem with the idle speed control logic OR possibly with the idle speed control valve itself.

[DesertHog]

Originally Posted by Bone

Not really, MOST idle complaints on EFI bikes (stumbling or running a bit high) has to do with cold startup.

This might be the first I've heard that is definitely when the motor is fully warmed.

My guess?

IF shutting it down and restarting didn't fix it I would say it COULD possibly be mechanical (say a vacuum leak that becomes more pronounced when it heats up to a certain point).

BUT because shutting it down and restarting makes it go away it's electrical.

Either a problem with the idle speed control logic OR possibly with the idle speed control valve itself.

Bone - I had the same thoughts regarding it being electrical in nature, thanks for confirming. It's due a service shortly so I think it will be in to the dealership and ask them to look at it again and take it for a TR if neccessary so they can witness the fault first hand.
Thanks everyone for your thoughts and suggestions.

[byidesign]

Go to the Forums for EFI/engine codes...and download the {how to} for engine diagnostics...then pull the codes from the scoots ECM .It sounds like you will find the "P0505"{loss of idle control} or IAC {idle air control,actuator} error code in the code storage..it is a warranty replacement ..just read the codes {don't reset} that way you can prove it has a problem to your dealer..
{see "how diag codes work" }posted in this forum
hope it helps
Bruce

[Bone]

Originally Posted by byidesign

Go to the Forums for EFI/engine codes...and download the {how to} for engine diagnostics...then pull the codes from the scoots ECM .It sounds like you will find the "P0505"{loss of idle control} or IAC {idle air control,actuator} error code in the code storage..it is a warranty replacement ..just read the codes {don't reset} that way you can prove it has a problem to your dealer..
{see "how diag codes work" }posted in this forum
hope it helps
Bruce

I agree it's a good idea to check codes himself.

But FYI, in the original post he said the dealer checked and found none.

Not that I trust the dealer necessarily.

IF the OP does check and finds a code, take a pic with a digital camera in case they deny it again...