i Have a 1996 1500 4x4 quad cab short bed with the 5.9L 360. I just got it back to running i did the plenum gasket, distributor, cam sensor, crank sensor, coil and all plugs and wires. i had it running good once the air was all out of the system. it got up to 80mph. i let it set a couple weeks and went to start it last night and ran good for about a mile then lost all power kept it running long enough to get home. Now every time it starts it runs for a couple seconds rough then dies. i took the fuel line off to see if there was pressure and it didnt seem like much. it was kinda like water coming out of the end of the hose. but after about 10 seconds it would shut off. Which to me doesnt seem right. you can hear the relay kick when this happens so i put a different relay in and still does the same thing. i was wondering if anyone knew what the problem was i dont want to throw a bunch of money and parts in it

 

The fuel pump will only run for a few seconds, UNLESS the PCM sees the engine turning. (either cam, or crank sensor signals clue it in to that.)

Need to put a pressure gauge on it, and see what you are getting.

 

+1^^ Def check the fuel pressure. Like hey you said, when you turn the key on the pump primes for about 3 seconds and then shuts off unless the truck is started.

 

this might be way off, but when I did my plenum I got a section of wire caught under the last bolt on the right side of the intake(left side if looking at it from the front) it was a wire for the fuel pump. My truck would not run as it was shorting out. Might be a easy place to look and see. Green or yellow wire I think.

 

how do i check it

 

need a gauge..... can rent one for three times what they cost to buy... or buy one for 25-45 bucks.

 

Although I agree the fuel pump is most likely no good. Of all the parts the OP has replaced , there is no mention what so ever about the cat and o2's. (unless of course I missed something)

 

The cat is gutted

 

i'd guess no crank position signal is triggering an ASD shutdown, which cuts power to the fuel pump and the coil.

you can scientifically measure fuel pressure with a gauge, using the test port, and check that its about 49 psi, +/- 5.

you can shade tree test fuel pressure by covering the test port with a rag and pressing the valve stem. if it squirts a big shot of gas out, then its got pressure. be careful not to set the truck or house on fire, or spill gas or smoke.

you can test voltage to the coil and fuel pump to confirm its ASD.

do you still have the original crank position sensor. if there was nothing wrong with it originally, i'd try putting it back in.