Andrew,

Diagnostic plug has four wires and should be on the left side under floor board. It may or may not have a cap on it. The only time I have had problems with no start after reaching operating temp was clogged system with LP sludge, low coolant causes LP to freeze or the governor throttle assembly is worn out. Could be a failing oil pressure switch. I will check on additional items and let you know what I find.

Disassembled the entire throttle body and thoroughly cleaned all components. made sure all jet ports on the diaphragm were clean. no change in the issue after about 30min the unit will bust on the 2 click. haven't used ether but just once to check if the issue was fuel related. do you happen to know how many wires the diag connector has that I can jump? currently running compression and leak down tests, but issue doesn't feel like either is the issue. thank you for your time.

Andrew,

Since you have replaced the regulator and diaphragm, I assume you have some knowledge of the LPG system. Do you see any of the lines or components getting frosty? Make sure coolant level is correct. Any codes or lights showing on dash? There is a plug that you can jump the A pin to the D pin, turn on switch, do not start and watch the engine light on the dash. This should flash 3 times 112, after that additional numbers would be problems. The plug is located under the floor board on the left hand side. How long would it need to sit before starting? Could have a fuel valve sticking or possible contamination. Since it only happens at operating temp, code for codes then. Separate the mixer from the throttle and check for buildup. I would say something on the fuel side is sticking when you shut down as it takes a small amount of ether to start. Careful with that stuff.