I have a 1987 swb with a rebuilt 2.6. The rebuild included a new fuel pump. Lately after driving about 30 or 40 minutes and letting the truck sit longer than 20 minutes, it will run about 10 or 20 seconds and die. I can crank the engine and it won't start. When I look at the fuel filter located just above the frame rail going to the carb, it is empty.I have pulled the pick-up tube and sending unit(the screen was perfectly clean) and blew out the fuel line. I can either restart by letting it sit a couple of hours or by priming the carb with fuel several times. The priming method usually takes two people, one to prime and one to keep working the throttle. Is this classic "vapor lock"? Do I need to install an electric fuel pump? My other Raider ran for 246,000 miles and never once did this and this is the carb from it.