Same issue on my 07 Street bob with v&h fuelpak. On some suggestions from forums I began not allowing the fuel pump to prime when hot, I hit the starter right as I hit the run switch. Since doing that I had no issues. I have some theories, but I'm not familiar enough with the efi system to know what is actually occurring. I want to say it is either the map is calling for too much fuel on start or a bad injector leaking through flooding the cylinder.

​​​​​​​Anywho, I just picked up a power vision but haven't had any real hot starts to see if it is fixed. One positive is the new map does not appear to be as rich on startup compared to the fuelpak.

 

Have you checked for trouble codes? Pull spark plugs when you're getting this issue. Are both plugs wet? Is your air filter clean? A cold bike doesn't mind a dirty filter, makes it richer, could be too rich when warm. Is everything tuned and in order; i.e.: plug wires good, coil tested OK, etc... coils when going bad often work when cold but fail when warm, although you say it's runs ok after starting. Try a warm start with throttle open 1/2 way (assuming you don't have TBW) If it's starts this way, may tell you it's running rich, could be leaky injector. Bit of a long shot, but maybe a weak battery or once running you have an electrical draw that is draining battery.

 

I would flash it back to the original tune and see if that fixes it. I have the FP3 tuner on my 2015 Fat Bob (had it on a 07 Street Bob as well) and never had a problem with any of the tunes.

 

Here's something different, heat the eng. head temp sensor on a cold eng. with a hair dryer or heat gun. If the cold engine fails to start with a hot sensor then I would think you found your problem.

 

Everything is fine from spark plugs to air filter. Plugs aren't wet. To bad for me that the PA weather isn't on my side right now so I will go out and pull the FP and run with stock settings. Well hopefully Ill be able to run it. I really hope its just the tune. Im getting no CEL lights or any other warning lights. Runs great minus a but of chop at a slow 1st or 2nd creep. That's what's making me believe its more of a tuning issue than none. BUT when it is hot, and I flip the fuel pump on And don't let it prime it seems to fire up. If I let it prime for a few seconds it throws a fit. Now I haven't played around with that a whole lot to see if it successfully starts each time doing it that way. Praying for a warmer day to take it back out.