Ive ordered a fuel pressure test kit. So i can attempt to look at the pressure under load. Thw current plugs have 13k miles on them i just looked at my records I pulled a few plugs and 3 cylinders are clean. #8 is fouling. So i put in a new plug in #8 and new plug wire. Ill drive it a few days and pull #8 plug again. Ive also ordered an ac delco coil for it as well. Pulling #7 plug wire the boot ripped. So its got a new plug and wire in it as well. So 1,2,6,7 are clean are a nice tan color at the base of the electrode. Maybe a tiny bit lean but not much. #8 was fouled quite bad. Upon installing the new plugs in 7, 8 i narrowed the plug gap to 0.45 as ive seen many references to it. If there still clean in a few days ill take the truck and rv for a ride to see if ive cured any thing. ill wait and see what happens with the plugs in the mean time. before i put in the coil that is suppose to arrive monday. Ill try and look at the other plugs tomorrow if not raining. To see if #8 is the only one showing any sort of fouling issue. On a side note the idle has come up a tad on the tach just putting a fresh plugs on the two cylinders mentioned. in the pic below #8 is on the left. #7 on the right. Sent from my PH-1 using Tapatalk