I commented above about this, it actually happened to my car. The pump overheated.
There were some natural gas kits sold that would not disable the fuel pump when you switched to gas. Some owners, when running out of gasoline, would switch to the gas. The fuel pump would keep running dry and melt. Something like this: http://2.bp.blogspot.com/_WafeVL7IZss/S5VP0fVNvuI/AAAAAAAAJP...
There were some natural gas kits sold that would not disable the fuel pump when you switched to gas. Some owners, when running out of gasoline, would switch to the gas. The fuel pump would keep running dry and melt. Something like this: http://2.bp.blogspot.com/_WafeVL7IZss/S5VP0fVNvuI/AAAAAAAAJP...