My truck starts for about a sec. Then shuts off
My truck cranks then shuts off just replaced fuel
filter and pump. Ran fine for about 3 days now it's
doing the same thing it did before I replaced it.
May be a leaky spider assembly, (injectors, spider lines, fuel regulator) Can check by doing a fuel bleed down test.
No leaks, plenty of fire , I think new fuel pump is bad it got wet. Maybe
Little fuel from shrader valve
Not necessary to tare into taking the gas tank down just yet, get a fuel pressure gauge and you may save yourself a lot of headache. Fuel pressure should be 56 to 63 lbs. That checks the fuel pump. Turn the key off and watch the gauge. Should not drop more than 5 lbs. in 3 minutes. You have a fuel issue since you say you have plenty of spark .
And the fuel pump is submerged in gas any way, they did that so it would run cool.
Looking for a Used Sierra 2500HD in your area?
CarGurus has 13,169 nationwide Sierra 2500HD listings starting at $3,500.
Search GMC Sierra 2500HD Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
GMC Sierra 2500HD Experts