Are you showing hours on the dash or a small round circle?
I have checked for a vacuum leak and there is not one and also checked the spark and it is good. I did not notice a code on the dash but once it is started the battery light flashes and a beeb starts.
One other thought..........check yer valve lash!
Is unit displaying a code? Make sure you have a good battery and the charging system is good and not trying to run system on low voltage. Next check for broken wires or shorted wires around the injector holder, coil over packs, and ETC. Then check LPG assist injector and for possible dirty last chance filter behind LPG pressure sensor. Let us know what you find.
I would check for vacuum leaks or loose, cut, missing hoses first. You must check the spark output with an actual spark tester. It should have 35K or jump 3quarters of an inch gap.
What engine is in there? Before replacing any fuel parts, make sure the tune up components are good. If they check out, then tackle the fuel. May be too lean.