I have a fella brought me his truck. Itstarted last year, truck started to run rough, rough shaky idle, and blue haze exhaust. He brought it into another shop that claimed the egr valve was bad, changed the valve, but made little to no difference. Long story short, drove it for a year running rough, and blue exhaust. Brought it to another shop, and said number 1&8 injectors were bad, replaced them, and now it has no difference. The other tech said that the cylinders were 10% lower than the others. I'm thinking that it is a fuel delivery issue because of the long cranks. What do you guys think?