hello all, i have been chasing a misfire on cylinder 7 on my 2000 chevy silverado with the 6.0 for quite a bit now. I have replaced spark plugs, plug wires, new fuel injectors, swapped coils around, changed manifold gaskets, inspected the valves and didn’t see an issue. does anyone have any insight on what to check next or how to proceed?

 

Welcome Andrew - please list your vehicle details so smarter folks than me can help you further

 

Is the check engine light on? If so, what is the code? Did you do a compression check?

 

yes i did and it was at 180 psi, the code is P0307

 

I'd say start with a proper spark test. I'm referring to one of those that light up when spark is occurring. You say you swapped coils around, which I'm assuming means you took a known good coil from another cylinder and swapped it, and I'm further assuming that #7 is still having an issue. That would lead me to believe it's the wiring for the coil that could be the problem. So really check to see if that cylinder is sparking at all. If it's not, you'll need to start tracing those wires. You could also look at the wiring schematic and check to see which wire is the one you want from the PCM and check that as it's coming from the PCM. Because I've had a PCM go bad before that wasn't opening the injector on one cylinder. Not saying that's your issue, but it might be the best path forward in your testing.