If the truck will not start when you first go on it than it is not a flow problem from a blockage that the regulator is not getting flow it is a bad regulator that is blowing to much gas pressure to the carb.if the truck starts and runs for about 5minutes and freezes up l would look for a restriction in the water lines to the regulator hope this helps

hi you need to pressure test the water system you will probably find a leak loosing pressure creating air lock in the system if not the regulator is faulty unit wont start with frozen reg