I have a machine that we replaced the engine in and first startup engine sounded ok but had no throttle response, took machine to dealer here in dallas was told to replace trim valves ,throttle pedal, electronic throttle body,and fuel lock off solenoid , after replacing all parts with new ones still won't start and I don't seem to be getting any signs of propane from the hose going to the new mixer. I'm about to pull my hair out with this POS , any body have any suggestions? Thanks