A few issues

[TerraformTom]

Recently, especially when this cold weather hit the mid-atlantic region, my engine has been 'hiccuping' or surging. And even more recently, I would say it is more like random accelerations. For example, I will be driving normally then randomly you can hear/notice RPMs increasing and accelerating for a split second or two. And this happens while my foot stays steady on the gas peddle. Anyone have any idea what this could be?

Also, my fuel pressure gauge off my diesel site CPR fuel system is reading over 100 PSI! Any one have any idea why this could be? I just changed my fuel filter today so I just need some help on where to start looking.

Any help will be greatly appreciated.