I have a 1996 K2500 7.4L Suburban that was running, but the lifters kept pumping down and rattling. I bought a used engine and it was very clean. It appeared as if it had just recently been rebuilt. Still had cross hatching in cylinders. I decided to step up the cam just a little and pulled the top side off to inspect it and decided to put a Comp Cams High Energy cam in it. I've replaced the timing chain (because I was in the neighborhood), and put it all back together. I change the distributor as the old one was bad in the cam gear. I just decided to replace it with a MSD. Now to the real problem. When I started it to break the cam in it acted as though it was running out of fuel. The truck had set for about eight months with no engine and full tank of gas, but as I said it had ran fine before it just needed to have a cam and lifters. It starts and runs, but tries to die, but you can keep it running if you keep working the throttle. The problem is that since this has shown up I've replaced the injectors, fuel pressure regulator, and the fuel filter. I put the fuel pressure tester on the fuel rail and it reads on startup and at idle about 45 to50 PSI. I've looked for the pressures and find them all over the board on what it should be at idle and etc. I believe it's the pump at this point. All things break at some point and it may have been time for it to start slowing down. The fuels here in Iowa not good (poor quality) right now too. Any other thoughts.
Mar 7, 2016 at 2:15 PM
