2 things if the pump is bad you may be dumping gas into your oil pan (pull the stick and smell for gas). Second take a small gas can and hook it up t0 the carb after the fuel pump. Let the gas can gravity feed the carb. If the truck runs on this set up it is the pump. I have seen pumps that will squirt gas with an open line but not be able to deliver enough fuel under preasure to keep an enginge running.
Good luck and have your fire extinguisher ready!
