When I replaced my 235 in my truck years ago I painted the engine cleaned and painted the engine bay . Both starter and generator rebuilt the engine would start up right away when cold but if the truck was warm the starter would turn the engine over but the engine would not start .The truck would start up right away if I rolled down a hill and bumped it into gear ,so I always parked on a hill while I was figuring out the problem .The problem was the ground after getting hot it was not making a good contact even when the starter turned over well when hot it seemed like there was not enough juice for the engine to get spark .