Ah, another owner of a hole in the water.
I'm not a diesel mechanic, but I've had a pick up with a diesel and have a sailboat with a diesel, so I know a little about them. Number one, does it turn over? If it's seized, then just plan on replacing it.
If it turns over, empty the fuel tanks (properly dispose) as old fuel will cause you grief. If possible clean any grunge out of the bottom of the tanks. Replace fuel filters. If it's just got the spin on type, replace em with a Racor water separating type. I'd suggest pulling the injectors and having them cleaned/calibrated (look in the yellow pages under "fuel injection"), although you could wait on spending the dollars till you can get it started.
After you get the fuel system cleaned up and some fresh diesle in the tanks, you will have to bleed the fuel system. Usually there's a handle and a bled plug on the fuel pump that will let you pump manually. Once you get fuel that far, you need to bleed it right up to each injector. Any air in the system WILL cause you grief.
Once you've got the fuel system in shape, and a fresh LARGE battery attached, it "should" start. As long as you have fule, air and compression, there's not much else. Most marine engines don't have glow plugs (looks like a spark plug, except they're all onthe same wire), if it does, I'd go ahead and replace them all right away.
One thing to be very careful with, if you have wet exhaust, while you're cranking the engine, the water pump will be pumping water into the exhaust manifold. There will be a "waterlock" muffler there to collect it, but if you spend too long cranking, it "can" back up into the exhaust valves and that is a very bad thing. If you're in the water, you can have a second person stand by the intake valve and leave it shut until the engine actually starts to fire (running with it closed will cause problems very quickly). If you're on the hard, you will need a big pail of water (5 gallon) and a live water hose. Route an intake hose from the raw water pump to the pail, fill the pail. Have your helper hold the hose and drop it into the bucket as soon as the engine fires. You should have water exiting the exhaust system within a few seconds of the engine firing up. If not shut down and find out why. After 5 years of non use, I'd strongly recommend replacing the impeller in the raw water pump right away (I'd actually recommend buying a spare, any gaskets required and having the tools on board to change, kind of like a save a dive kit, it's part of the save a trip kit).
If you'd like to continue this you can PM me for an email address.
Kent
Good luck
