The propane test was one of the first things I did. Then I adjusted the idle mixture screw as Carl suggested and it definitely has an effect on the engine.
Bartamos, The choke is operating correctly and the truck runs better with the choke in/open when warmed up. If I pull the choke out a bit I can tell it's running rich.
I drove it around all day yesterday running errands and it ran fine. It's hard to diagnose an issue that appears and dissapears of its own accord.
