OK lets start at the beginning, I have a 98 K1500 had a problem last winter and replaced the fuel pump, turned out it was not the fuel pump and it was something else, never did really figure it out.Truck has run great for 8 months. Fast forward till this last saturday, Left house got fresh tank of fuel drove about 6 miles the truck starts bucking like it was either running out of fuel or had a tank of water. Truck dies have to get towed, check for water , no water in fuel, ck fuel pressure ah only 18 lbs fuel pump , change fuel pump [ under warranty] thank you, hook all up truck won't run ck fuel pressure 16lbs WTF, so I pull fuel pump again [ pumps are airtex] so I say they are no good and I bit the bullit and go find and buy a Delfi unit install it into the truck, same thing no fuel pressure 19lbs, WTF . so I pulled fuel filter installed new one, same started checking FP along fuel line, at filter , at pump, all the same. no blockage. So for piece of mind I got a battery and wired pump directly , pump came on pumped up 61lbs truck ran, ok pump good, must be wiring, checked all wires , did wire up date, checked resistance in wires all good, replaced fuel pump relay. It seems that what ever controls the pump for it to prime up to 61lbs is shutting off to soon. And because it holds right at 61lbs tells me that the FPR is working properly. I replaced the oil pressure switch and tried a known working CPU from another truck and it still does the same thing. I am lost with this thing. I even reset the security, with the 3 -11 min cycles. Any help would be appreciated. Thanks in advance. HJFisk

 

OK found the problem with this truck, It was a bad ground, the ground wire to the frame on the right side of the truck by the starter[ braided cable] looked ok but when I grabbed hold of it it disintegrated in my hands, and also the one going to the cab which attaches at the same bolt was bad then I ran a new ground to the pump it self. Apparently it had ground enough to run but not up to the speed in which it is suppose to, and be able to come up to pressure. I struggled with this for 3 days before I found what was wrong. Everyone searching for info on the subject don't be like me CHECK YOUR GROUNDS. I changed the pump twice for nothing, probably first one was good. Glad the truck is fixed but it has been a hard lesson learned.. GROUNDS< GROUNDS