When I started the truck today after it had been sitting roughly 18 hours, I noticed a high idle and heavy miss. I let it run about a minute, and when under load, the miss went away. I turned a corner and as I went up the hill in 3rd, it stalled, then caught again running on maybe 4 cylinders. I stopped in a parking lot to check my UVCH connections, and it stalled. It restarted, but had very little throttle response. I removed the chip, and it restarted and ran to the point of being driveable, but still had a bad miss at idle. Only under load does the miss go away. I have new UVCH harnesses at the house, so I may swap those in. The glow plugs are a year old, the injectors are a year old, and the Stan-Cor relay is less than a year old. Yesterday when driving I noticed a slight miss, but nothing like it was today. Removing the chip seemed to help, but only slightly, which I thought was odd. Any suggestions?