So after battling a P0308 after my HG job, and replacing just about everything in the path I wanted to start a new thread for possible mechanical issues and further troubleshooting.

For those who weren't aware, my original thread is here, and outlines the steps I took in replacing bits (coils, wires, plugs, injectors, etc). After replacing just about everything I'm still left with what looks like a single misfire on Cylinder 8.

My thoughts now are that it may be something mechanical with that cylinder. The valves, or something with the rocker arm? I'm starting to stretch my mechanical means at this point. I re-used the rocker arm assembly and pushrods, though I did store the rods in correct order.

I'm thinking about taking it to a mechanic to have them do a proper smoke test and compression/leakdown test before I tear back into it. Thoughts on next steps I should look at?

 

I wanted to follow up to close out my own post.

I tore everything down to the rocker assemblies. I soaked the rocker assemblies and rocker covers in a strong degreaser (PurplePower) to clean them up. They were filthy. I also replaced the oil separator while I was at it. Nothing else was replaced besides the necessary gaskets/orings. After putting it all back together my misfires are gone. It could have been a very dirty/stuck rocker assembly component or an electrical connection that was reset more securely upon reassembly. Who knows. I'm just glad to have my Rover back!

Here is a pic of my initial reassembly with half-assed cleaning of the rocker assemblies:

Here is a pic after tearing back into it and giving the rocker assemblies a proper cleaning:

 

Man, glad that youre back.