yesterday i was driving and pulled in to a parking lot after 5 miles and when i was slowing to a stop in the parking spot it started stumbling and died. i tried cranking it over after that but it didnt fire. however it will start if i hold the pedal down for a few seconds and pump it. it also started to die more than a few times when i was driving, first time when i wasnt loaded and the second time i had a bed full of furniture and stuff. does this sound like a fuel pump? no codes were thrown, has a new fuel filter, and the top end was rebuilt after the timing chain snapped.