I've been through a few threads about CP3 pumps, air leaks in the fuel system, and injector problems, but I have yet to see anything that can solve this one. I have an 03 LB7 with about 260,000 miles on it. I was getting the typical white smoke at idle problem so I installed all new injectors and high pressure fuel lines. The truck ran great, and I drove it for a month, but then I got the great idea to change the CP3 pump because of the mileage. Of course, now I can't get the truck started again. I changed the fuel filter housing, filter, and low pressure hoses. The truck still wouldn't start. I disconnected the return line at the quick disconnect, clamped clear tubing onto the return line and ran it into a container. I noticed that when pump up the system with the hand primer, it pumps up hard, but slowly loses pressure as the fuel trickles from the return line into the container. Is fuel supposed to come out of the return line just from the primer pump pressure? When I crank over the truck, no more bubbles come from the return line, so it's not sucking air anywhere. I loosened the high pressure fuel line nut on cylinder 7, cranked over the engine and fuel poured from the fitting, and also slowly from the return line. How do I know how much pressure is in the rail? I have no idea where to get a pressure gauge that can handle those high pressures. I rented a code reader, and the only code showing was P0700 (Tran Ctrl Sys Error). Anyway, the fuel system isn't sucking air, but I just can't get the truck to even sputter..any ideas?
Edit: I unplugged the jack from the FPR and that also did nothing. I'm beginning to wonder if the fuel pressure relief valve is stuck open.
Edit: I unplugged the jack from the FPR and that also did nothing. I'm beginning to wonder if the fuel pressure relief valve is stuck open.
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