got in my truck today to drive it after its sat all week and i take off down the road and when i go to excellerate it starts stumbling and fall on its face. i checked the timeing and i think it looked ok, i have 77 or 78000 miles on the motor do you guys think its an injector problem, i replaced the fuel filter a couple years ago and just this past 2 months or so put a used gas tank in it and new sending unit and pump. fuel gage is showing 1/4 tank. so where should start, pressure check the system and if i do what will that show me. thanks for the help, chris also this on a 93 chevy 4x4