Questions
 

Okay, I need some assistance. I dont know everything that I wish I knew about my truck and I have a couple concerns that I dont know what to think or even where to begin. Firstly I have a odd vibration I get when I accelerate to get onto the highway it lasts for a few mintues and than goes away. The other thing is I have this odd feeling somethings wrong I think its running rough but I didnt think much of it until i heard some kind of knocking sound of sorts under the hood. I keep getting this random Piston 4 misfire and it comes and goes but we have already replaced the plugs and wires so I dont know what to think. Can anyone shed any light on these things.

Please and Ty

What brand did you replace the plugs and wires with? These trucks only like delco. Hae you replaced the dizzy cap and rotor or checked it for signs of corrosion and arching? Where does the ibration feel like its coming from?

I dont know if the plugs or wires are Delco but I will have to look into that. I feel the vibration in my seat but it feels like the whole truck is shaking.

As for the shaking you either got a bad tire maybe out of balance and possibly a bad ujoint in one of your drive shafts.

^^^+1, check out your tires first. And looks into the cap and rotor. Most misfires are caused by a fault in the ignition system.