i ran my pickup out of gas one time so i put gas in it got so it would run but not good so i put a new fuel filter on it and i pressurised it like thwey say in the hanyes book and then it ran for a while then quit now if i depressurize the fuel sytem by pressing on the sherder vavle then re priming it i can it to run for a while the pump runs while the engines is running im not sure what it could be i know it has low fuel pressure but im not sure what to do any help?