Thanks. Good info there. Looks like one of the fuel solenoid valves is getting stuck and flooding the engine.

Sorry I was thinking Clark with Mitsubishi 4G63. COP is coil on plug.

if you are 'over fueling' [flooding the engine with too much LPG]' you may be able to at-least get a little fire going by disconnecting the hose from the LPG tank waiting a few minutes then trying.
can you define what you mean by "COP ignition",
the codes in this truck are accessed by the accelerator pedal. have you checked on the woodward fuels website? search 'MI-04 woodward fuels' and they have considerable information on this truck's emissions controls system.

No distribiter this engine has COP ignition

If the no start is due to too much fuel ether wont help, shut off the tank and try to start it, it may be over-pressurized. Is spark going to the right place at the right time? Check your cap I once had a Mitsubishi/Cat that would run, very poorly though, with the cap in my hand, your could see cross firing in the cap and when the spark hit the right cylinder terminal it would try to run, with the cap on the distributor it would not run, this cap only had 300 hours on it so I automatically assumed it was good. If you have spark, fuel, and compression the engine should run.