I have a single miss (used to be harder) at 1800 rmps.

Just replaced the injectors and the miss is not as bad but it is still there. Happens around 60 mph and 40 something miles per hour.

It is still there in spite of new: ops, lift pump, ip, glow plugs, shift solenoids, and recently injectors. I needed all these new parts anyway but I had convinced myself that it was the injectors. So I was disappointed when after changing them out that it did not fix the problem completely. However the truck is running much smoother and has more power.

I have also run the truck without the filter harness and that did not help.

Any other Ideas?

I have not tested the fuel pressure while driving yet. What is the best way to do that?...just hook up to the t-valve and run a gauge back to the cab?

zip tie a fuel pressure gauge to your windshield wiper. See what your fuel pressure is before buying any more parts.

I was thinking if there is a way to check the filter harness or if there was an updated filter harness for the optical sensor. I think the fuel pressure gauge sounds like a good idea.