My Iron did pretty much the same drove me bat **** crazy. Due to no trouble codes I recorded the speedometer not working etc on my phone. Also it only did this once it was warmed up. Harley said they were unable to replicate it. Until I told them it had to be really warmed up. He put it in the Dyno room and presto she acted up. After replacement the bike ran much better.

 

I installed the VSS & IAC a few weeks ago, and no issues since!! I'd say I have about 200 miles on her since then, so not too many but next week I'm heading out on a 2500 mile ride to the HD Softail factory in PA so she'll get the REAL test then!

 

good post. my bones is idling weird lately...not stall but on verge.

can this be replaced without removing the wheel or guard? how much of a pain is it?

 

I managed to replace without removing wheel.
It is really tight, but possible.

 

How does one replace the VSS? I can see it, touch it, but can't get a hex wrench in it to remove the bolt. FYI - I came across this thread yesterday, on my ride home the speedo started acting up....reading 120MPH while going about 50 in traffic. I made one stop and after starting up again, the speedo worked fine. Given the intermittent problem, I figure I would just go ahead and replace it.

 

The manual spells it out nicely. If you don't already have one, it was the best investment I ever made with my HD.

Let's see.... rear wheel, splash guard, computer block, and electrical panel being held on by 3 bolts. After all that's off, the VSS is staring you in the face. Then it's easy to replace!!!

 

Get a manual. I replaced mine on a a 2010 Fat Boy without have to take off the rear wheel. Pretty easy to do. It just nuts and bolts. There is a thread on here with pics and instructions that made me go ahead and do mine.

 

Small update:

Couple days later, idle problem is back.
At the end I also had to change IAC.

300km later everything still OK.

 

Well, this VSS issue seems to be an ongoing ordeal.... I have a brand new 2015 Iron 883 and after about 1000 miles, my speedometer began to drop to zero whilst riding. I'm still under warranty, but I think I might try to simply replace the VSS myself and see if the following stops happening:

 

It's happened to me twice on my 2005.