The other day as i was cruising down the highway. I got to an overpass, and i felt a jerk in engine like a misfire. Now it dose this at every overpass at cruising speed. If i am on the accelerator hard it dose not do it. My first thoght was oh i need to change plugs, but for grins i put my prolink on it, and i have a code for low fuel pressure system pressure too high. I hooked up my fule pressure guage, and i am runing a 65psi and almost 70. I dont know specs, but would this high pressure cause this mis. P.s. I am a diesel tech. By trade so go easy.

 

It was the spark plugs. I pulled them out and the tip was so far gone it looked like an .080 gap. Put new plugs in gaped at .040 and now its 100% better.

 

Still no idea what the fuel pressure should be out of curiosity.