I cleaned the injectors for now. Number 8 had a little trash in the inlet side, so other than that they look great. The truck only has 150,000. The distributor was trash. The gear was severely worn. I bought a new aluminum distributor and the truck runs much better. Before replacing the dist. I was getting hard bucking around 2500 rpms, but no codes. I had planned to replace the cam position sensor since it controls the injector firing (it felt like a fuel problem). The distributor came with everything -- nice part for $109. All is good now.