Ultra classic problems
Seasoned HDF Member
Joined: Dec 2005
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From: poway
An 08 does not have a IAC port. It's a servo controlled butterfly.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,894
Likes: 8,002
From: poway
Hey yall new to the forum but looking to get some help. I have a 08 ultra classic no mods other than a dragos bike works exhaust, bike has 28k on the odo. So the issue ever so often Ill be riding and it will die, drop rpms, start then backfire. I have no idea what the issue could be and the only thing that seems to help is disconnecting the battery for a few hours then problem goes away for a few days. When it dies it takes a few seconds and it starts its self again. Its almost like its key banging itself. Any help would be greatly appreciated.
I assume that in the vid, that the tack bobbles about and the you haven't pulled the clutch in. If that is the case, I'd suspect a poor connection on the run stop switch.. Try toggle it a bunch of time with the ignition off.
Seasoned HDF Member
Joined: Feb 2007
Posts: 6,081
Likes: 1,127
From:
Consider starting and letting bike run in neutral while parked.
Get a rubber mallet and tap hard parts to introduce vibration.
Handlebar ends, axles, shock ends and so on.
A stumble of motor after a tap might help you isolate area.
Perhaps there is a cable someplace that is cut and barely connecting.
Get a rubber mallet and tap hard parts to introduce vibration.
Handlebar ends, axles, shock ends and so on.
A stumble of motor after a tap might help you isolate area.
Perhaps there is a cable someplace that is cut and barely connecting.
Road Master
Joined: Aug 2019
Posts: 786
Likes: 177
From: wv
My 2009 FLHR did similar as yours and turned out the fly by wire plugin on the side of the throttle body i cleaned and lubed the plugin and tied the wires down for vibration and no further issues since 2019. Hope this helps.
Seasoned HDF Member
Joined: Mar 2021
Posts: 18,250
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From: backwoods
Do the lights and rest of electric stay on? Have you changed handle bars recently?
What years have it?
What years have it?
Stellar HDF Member
Joined: Aug 2011
Posts: 2,765
Likes: 1,802
From: Newnan, GA
Hey yall new to the forum but looking to get some help. I have a 08 ultra classic no mods other than a dragos bike works exhaust, bike has 28k on the odo. So the issue ever so often I’ll be riding and it will die, drop rpm’s, start then backfire. I have no idea what the issue could be and the only thing that seems to help is disconnecting the battery for a few hours then problem goes away for a few days. When it dies it take’s a few seconds and it starts its self again. It’s almost like it’s key banging itself. Any help would be greatly appreciated.
The same symptoms happened to me. When I finally got home (via tow truck), the first thing that I did was check the codes. All the codes were related to the throttle body and the throttle. Don't ask me what the codes were, this happened last Nov at 12 midnight coming home from work and I was tired.
I started looking around the throttle for anything loose or torn wires. I made my way to the throttle body. I found the Throttle Body plug was loose
. I pulled the plug out to find the weather strip was torn in such a way as to prevent it from fully seating into place. I can't see this happening by itself. I have my suspensions how this happened but that is another story for another time.I removed the rubber pieces from the plug and the jack, reinstalled the plug with no additional issues and the bike fired up and ran smoothly without throwing any more codes. The next day I ordered a new plug that came with silver plated pins and a new weather seal.
After I installed the new plug, the bike has been running well ever since.
***This may not be the same thing that is happening with your bike but it is worth a look to see if there are any issues (corrosion, broken wire, mechanical fit issue) with the throttle body plug.***
There was another issue that the bike had about a year ago. The ignition switch was intermittent and I replaced it (that was fun LOL).
Look at the battery connections, look for corrosion and loose connections. While you are there, Look over the ECM, the plugs and wires for any damage.
Max recommended a good idea, check the kill switch.
Check any work that you recently performed to see if anything is out of place, loose, or broken in the area.
Check the condition of the ground cable that is attached to the top back part of the transmission case.
Good luck.
Last edited by Mongo1958; May 31, 2025 at 08:43 AM.
Club Member
Joined: Apr 2013
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From: Cape Cod
IAC was on the 2002-07 ELECTRA GLIDE and others.....
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Stellar HDF Member
Joined: Aug 2011
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From: Newnan, GA
+1
Seasoned HDF Member
Joined: Mar 2021
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From: backwoods
Delphi? So starting with 2001 softail?
For some reason this appeared to be more of a problem on 2007. Or maybe just cause I bought one, But I seem to remember people talking a lot about 2007. There is a bulletin from harley, I don't remeber years. I fought it under warranty. First they jacked idle up to 1100. Which is not a bad idea, but it shows they didn't know why or how to fix, But I still raised it back to 1100 after my last map lowered it a little.
For some reason this appeared to be more of a problem on 2007. Or maybe just cause I bought one, But I seem to remember people talking a lot about 2007. There is a bulletin from harley, I don't remeber years. I fought it under warranty. First they jacked idle up to 1100. Which is not a bad idea, but it shows they didn't know why or how to fix, But I still raised it back to 1100 after my last map lowered it a little.