Had the pump and injectors rebuild by a very reputable company but I still seem to have a slight miss thought it was air in system but after running it for an hour it's not any better. Took valve covers off and cant see any obvious bend push rods. Removed energy cells and they all checked out. It all started this fall was working it on the chisel plow and noticed it had developed a miss when stopped to change a shovel. Put it back to work and cleared out but now it's not clearing up at all. Short of pulling the heads is there a way a guy can measure the lobes on the cam before removing the heads. I'm thinking it's either that or a burnt valve. What's your guys thoughts?