My thought on the pressure change is more of a major and sudden difference when it wasn't in use. Started fine at sea level and in the Mountains.

I just remember going on road trips and having ammo cans become almost impossible to open up, or propane tanks leaking from the pressure difference. My thought was maybe the internals of the engine where at one pressure and the outside drastically another where it effects a few operations, maybe making a little bit of a suction like a jar of jam. If it had time to adjust maybe there wouldn't be anything, but if it swings greatly in a few hours, maybe it's pushing something that's already weakened. It feels more like it's pushing through something and drawing more power than it is just not having enough to start normally. (I'll try to get a video)

I know it's a bit of an 'eye brow raise' idea but it's seriously the only thing I've seen in common with this issue. Yesterday my gas range went from over 60 miles when I parked it to 10 miles when I started it up to leave work. Gauge also read a lot lower. Just makes me wonder if the air pressure could have pushed things in the line a bit more since the tank was almost empty.

 

I've never owned or worked on an injected Harley, so some of this may not apply...

Hard to say without knowing exactly what the computer(s) are doing in the background. Range is often a calculation based recent average mileage (injector pulse width, RPM, etc) that may or may not be including an electromechanical float measurement. The polling frequency could be anything from instantaneous to once per ignition switch cycle to once per tank.

Altitude and barometric pressure are closely related amd should be measured at least once per ignition switch event (off/on), likely by a MAP sensor. It could also be polling at various frequencies, similar to the fuel range calcs.

Again, without knowing exactly how the computer is reading amd reacting it's all speculation. That said, I'd suggest giving the ECU a second or two to take new readings each time before starting the engine. Turn ignition and kill on (sequence may or may not matter...not sure), count to 10, then start. It may or may not help.

Obviously, all the sensors must also be working properly. In this case, your looking at MAF, MAP, fuel level, injectors, and maybe TPS.

The ACRs either open or they don't. They're electronic solenoid valves, basically just like injectors. Make sure the ECU has the latest firmware/tune and that the ACRs are actually cycling.

 

 

Finally got some video


Good start, taken this morning after sitting for 2 days in my garage:


Rough start after sitting at work for 9 hours, same day (looks like I started the camera a second later, and that might be the miss of start up sounds, honestly I wasn't paying attention for them):


Bike was parked next to the building under an awning. It's not the worst it's done it. Took me about 10 tries to come across a video of it doing it.

 

Not looking to bump this all the time, just posting what's going on for anyone in the future as it might be a weird gremlin, lol.


Did it again today, back fired and died rather than catching. Starter button was released and reapplied (without turning it all off) and it started right back up. It did make the standard start up sounds, I was listening this time, lol.

This weekend I'll freshen up my connections best I can. Even though the battery was ruled good when they tested it, I haven't fully ruled it out, but I'd rather not dump $160 on a battery on a whim, especially when its as erratic as it is.

Today I took the Volomod off. My thought was that maybe it was confusing the ECU somehow. One of the very first times it had this problem it did sort of spaz it out, causing the 3rd rear light and the lamp it was connected to to blink. So enough of a surge happened to either charge it or confuse it. Went away on a 15 minute ride. (The Volomod is a unit that has a sensor to flash a 3rd brake light. Basically when your bike dives a little from breaking it starts flashing, when you dive hard it flashes faster. It also flashes the 3rd brake light slowly when you're stopped and are applying the brakes.) It's possible it was messing with the CANBUS system which from what I've come across 2013+ Harleys have. (unverified though). My previous bikes didn't have CANBUS and after searching their site Volomod doesn't recommend using it on bikes that do, maybe this is why.

It did have it on for about 4 months and 2,000+ miles without issue, but maybe when the weather changed it had a combination effect. Here's hoping. If it does it again I guess I'll take it to a dealer and show them the video I have.

 

Maybe you're loosing voltage at the starter solenoid, making it crank slower. Next time, as soon as you identify that it's cranking slow, stop for a moment and try again. Each time the solenoid makes contact you get a "fresh chance". If the solenoid is the problem, it will get worse with time.

 

Thanks, I'll have to give that a shot if it pops up again. I'm used to them on old cars where they either work fine or you have to hit them with a 2x4 while cranking it, lol.

Suppose I need to look into the relays too, not sure what they could effect.

 

Yesterday it happened, and I tried letting go and hitting the button again and it worked fine.

Since it's still under warranty I had them check it out this morning, took a while for it to do it for them, but they're going to replace the starter and battery next week for me.( Nice to have a warranty, I'm used to cars from the 50s and 60s so every problem is mine to fix lol.) I was starting to suspect a compound problem, half the symptoms seemed like a battery half seemed like something unknown, like it starting perfectly if I immediately retried.




Thanks fir the help guys. It's genuinely appreciated!



****To anyone in the future with a similar problem if I dont post again in this topic about it happening again it was resolved from replacing the starter and battery. Wish I could just edit the first post to say that...

 

I would take the starter solenoid apart and clean it out real good. My 2002 RK does this occasionally and a clean solenoid plunger works wonders.