Here are some notes from when I did mine:
ZD11 Motorcraft glow plug is best
1. Disconnect the batteries
2. Clean up the valve covers with some mean green before removal. Wash down with H20.
3. Disconnect map sensor and any other electrical wires that might get in the way. Intercooler tubes should also come off (cover holes). Also, take off the heater hose brackets on the valve cover two bolts. To remove them take a screwdriver and pry up from the bottom.
4. Remove the intake tubing up to the turbocharger inlet and cover the holes.
5. Unbolt the valve covers-the only difficult bolts to reach are the ones in the back by the firewall. Patience and flexibility will help you get them out. On the passenger side: The oil fill tube unscrews counterclockwise. (This makes it easier to get the valve cover out.) 6. Disconnect the glow plug electrical connection. If you are replacing the harness and valve cover disconnect the injector wires at the injector.
7. With a deep 10 mm socket and 1/4 inch wrench with an extension, lossen the glow plug.
8. Get a small diameter vacuum line 6-8 inches. Slip this over the end of the glow plug to remove. Make sure it fits tight over the end of the glow plug. If you try to undo the glow plug all the way with a socket it will get hung up on the rocker arm and you can't get your socket out. Don't drop one in the abysses.
9. Drop new glow plug into the hole using vacuum tube, spin into place by hand if possible, and then use socket to tighten.
10. Torque specs:
Glow plugs: 124 inch pounds or 14NM
Valve cover bolts: 97 inch pounds or 11NM
Injector hold down bolts: 120 inch pounds or 14nm
rocker arm pedestal bolts to 20 ft-lbs
11. Put the UVC connector back onto the glow plug.
12. Repeat for other 7 cylinders.
13. Check UVC harness for stripped insulation/loose connections/etc... and replace if necessary. Also make sure no wires are touching any moving parts.
14. Make sure all electrical connectors are connected before putting the valve cover back on. May be a good idea to ohm out I to c and glow plug to ground before putting back on the valve cover. The pins will be arranged like this:
G - G - I - I - C - I - I - G - G
G = glow plug
I = Injector return
C = Injector common feed
You should measure .5 - 2 ohms between G and ground, and around 3.5-5 ohms between I and C.