M119 92 500E engine miss

[turbodiesel]

I bought a project 500E with 157k miles. First thing I'm tackling is a slight engine miss at both idle and at speed. You can feel it at idle sitting at a red light, and at speed at high RPM.

I have inspected the plug wires and they are recent and look fine. They are Beru brand. I pulled one plug and it did look somewhat worn (grey powder all over anode). I was able to pull one plug wire at idle and have the miss not change, thinking I was on to something. Then I went and pulled another one, and it did not change either.. I am thinking this is a miss across all 8 cylinders.

I am wondering if this is a common problem/common fix. Any help appreciated!