ORIGINAL: JoelP
My P-120 was upgraded to 6.0 version and is doing something similar. On start up, the turbine ignites on propane, rpm's increase slightly, then it just runs on propane until I get ACC SLOW and it shuts down. The only way I can get it start and keep running is to shake the propane can really hard.
I had a similar sort of experience with a newly repaired Jetcat - timeouts and failed starts etc unless I bumped extra propane in. Turns out that the EGT probe got bumped sometime during packing / unpacking / installation, such that the probe was not sticking through the hole in the tailcone and was instead just touching the tailcone. As soon as I fixed the probe, it behaved like a Jetcat again
May not be the issue in your case, but perhaps worth checking anyway.