if it's a 24v, and I suspect it is, it sounds like the VP44 died on you---it's normal for the lift pump(inline pump) to run for 20 seconds or so after you turn the key off---but as posted earlier we need year of truck and what modifications you,ve done to it---have you changed the fuel filter lately?? you can crack the (starting from the front and counting towards the rear) injector line nuts on #3, #4 and #5, go crank the engine over for 15 seconds or so and go check to see if you have fuel coming out of them, if you do then button it up and see if it will start---if you have no fuel at those lines after 3 cranking tries then your VP44 is most likely dead---if you can get a code reader to check codes that would be helpful--if your truck is a 2001 or later you can turn the key on and off(don't start it), just turn the key on and off 3 times and some #'s will flash in the odometer--write them down and post the info here-----chris