I purchased an injector tester for Mercedes diesels on ebay ($190). I found out I need shims and nozzles. Cord at Sun Diesels is checking with his Australian division to see what they can get. The nozzle has a number on it, NP-DN0PDN112. The pop pressure is supposed to be 2200 psi (2134-2276 psi). My injectors 1-4 tested at 1700, 1800, 1700, 1800. The shims 1-4 were 1.37mm, 1.25, 1.32, 1.25. The nozzles were all dished on the combustion chamber end, and the spray patterns were awful.

Glow plugs come with different voltage specifications. I don't know why. I found an NGK part number for 4D56 glow plugs: NGK CY57. Don't know if it's the right number. 4D56 glow plug prices seem to vary from about $8.50 to $40.00. Don't know why. I got some from GB that were claimed to be genuine Mitsubishi. They were not. They took two weeks to get here and they look cheesey next to the OEM's. I tested them in the air. The OEM plugs glow along the entire 3/4" tip, the replacements only glow for about the first quarter inch.

Seattleraiders said to use a voltage regulator ahead of the solenoid to protect the glow plugs. I spent a little time looking for one but sort of struck out. There are some Ford and GM controllers for about $150 on ebay. I wonder if they would work. I wonder if a voltage regulator is necessary. The plugs take a while to start glowing with 12v, say about 5-7 seconds. It's not like they snap to attention and look like they will melt. I wonder if the extra volt does damage. I would worry more about it after the engine starts and the alternator ups the system voltage to 14v.