1998 GMC K1500, 5.0 Vortec, 55K miles.
have been experiencing an intermittent misfire at the 60-70mph mark on the highway, it's a multi-cylinder misfire, usually 2-3 cylinders. The entire fuel system was replaced, Fuel pressure is reading within GM Specs. Within the last year, it has received, plugs, wires, cap, and rotor(feb 2023), MPFI Injector update(march 2023), Intake manifold gaskets, and a New coil and more that I'm forgetting I'm sure. the fuel pump, filter and lines were replaced last week and it helped with the misfire however it's still doing it and I'm not seeing or finding a visible reason behind it. Does anyone have ideas? Part of me thought to spark issues however its not consistently doing on it the same cylinders or with the same intensity. Possibly bad set of injectors? Right now im stuck on possible, Bad cap and rotor, failing ICM or coil, and the injectors.
have been experiencing an intermittent misfire at the 60-70mph mark on the highway, it's a multi-cylinder misfire, usually 2-3 cylinders. The entire fuel system was replaced, Fuel pressure is reading within GM Specs. Within the last year, it has received, plugs, wires, cap, and rotor(feb 2023), MPFI Injector update(march 2023), Intake manifold gaskets, and a New coil and more that I'm forgetting I'm sure. the fuel pump, filter and lines were replaced last week and it helped with the misfire however it's still doing it and I'm not seeing or finding a visible reason behind it. Does anyone have ideas? Part of me thought to spark issues however its not consistently doing on it the same cylinders or with the same intensity. Possibly bad set of injectors? Right now im stuck on possible, Bad cap and rotor, failing ICM or coil, and the injectors.
