Yes, I'm having the exact same problem. I've been able to narrow it down to a specific set of circumstances though, so that's helped me figure it out in my head a little. I'm getting ready to pull the truck in and start taking a bunch of stuff apart, I have a huge list that I'll be working on.
Back to the circumstances. My truck long cranks if it has sat for at least 10-15 minutes. Hot or cold engine, hot or cold ambient air, doesn't matter. If it has sat for less than 15 minutes, it fires right up.
Also, say I know it's going to long crank because it's been sitting for a while. Instead of just cranking and cranking until it catches, I crank it the first time for about 2 seconds, and then let off. Then "usually" when I crank it the second time, it starts immediately. Also, I definitely get a fuel smell in my exhaust after a long cranked start.
All that leads me to guess injectors are the issue.
The first thing I'm going to do is take the IAC apart and clean it real. If it's super dirty, then that might be the issue. Second thing I'm going to do is take all the injectors out and test the resistance. From what I understand I should get between 12-15 ohm's. Then I'm going to send them all to
WitchHunter Performance - Injector Cleaning & Flow Testing Services and have them serviced and cleaned. After that, if I still have the problem...it's probably an ignitor or the actual ECM having issues. I hope it's not.