I had a hard time finding good information on this problem.
P1316 codes are usually followed by more codes that some scan tools can't read. Check all the wiring to the valve covers from the IDM for chafing or shorts to ground. If you got a P1316, that means there are codes stored in the IDM, maybe circuit opens or shorts to the injectors. The codes will be reported when the buzz test is run.
From another board:
"I've had a CEL on for about 2 weeks now, and then started experiencing a serious loss of power and very rough idle. Pulled the codes and it showed P1316 - IDM Codes Found. Started reading around and found that the problem was likely a faulty clip that holds the under valve cover wiring harness in place. I checked the wiring bundle that goes from the IDM to the valve covers and it was OK. Not chafed up or anything. I pulled the valve covers and both of mine were loose. The drivers side was about 1/16th of an inch out, and the passenger side was almost a full 1/4 of an inch. After I picked up two new harnesses from International for 19.78 a piece, pulled the old harnesses, and installed the new harnesses, she's running like a top again. Overall not a bad job, and I saved a few hundred off the dealer considering the parts were only 40 bucks and 2.5 hours of time. If anyone else has this problem, buy the International parts, they're about 40% the cost of Ford. Here's the part numbers...
Wiring Harness, Injectors & Glow Plugs
If your harnesses are good, you can just use the Retainer clips for the UVC
Hope this helps!