montuckyz

Hello,
I'm new to cf but I have a problem with my 98 silverado 4x4 5.7L that I can not figure out. First it started out as a hard starting problem, i would crank and crank then about the third crank it would start, then one day it started stumbling and felt like it was missing like really bad almost to the point of dying. after I parked it the next morning it would crank and wouldn't start. I put a fuel pressure guage on the fuel rail and when the fuel pump kicked on the psi went up the @ 60 but as soon as the pump shut off it bled right back down to 0. I figured out it probably was the FPR so put a new one on and the pressure hit 60 and stayed, it fired up instantly but the gasket in the center of the plenum had slipped down and created a massive leak and the engine surged and then stumbled and missed and just ran all erradically and had a massive sucking sound it did throw a code 1345 and 300 crankshaft/camshaft sensor and random misfire and would almost die so I removed the plenum and reseated the gasket after putting it back together it wouldn't start again, put the pressure gauge on again and pressure hit 60 then bled back to 0 after pump shuts down. took plenum off again to see if fuel was coming out of the vacuum thing on the FPR when i keyed on and the fuel pump turned on, only I didn't hook up all the connections just the fuel lines and the huge harness connection next to the lines, when I key on at this point the fuel pump only kiks on for 1 sec and then immediately shuts off pressure only hits about 15 if i key off and on repeatedly I can slowly bump pressure up to about 45 but it still bleeds off? does anyone have any suggestions cause Im going freaking nuts with this thing.