Disabling glow plugs is a good idea, even though i've never bothered.

And I used Ether lots of times in my 7.3


Turn your key on, wait for the Wait To Start Light to go out, then once it's out, wait untill the clicking you should hear stops, then have someone crank the engine over, let it cranking at least 5 seconds, then give it a lil bitty shot of Ether at the end of the cold air intake tube. (DO NOT SPRAY DIRECTLY IN INTAKE) It "should" start right up as mine did. If it doesn't. Try a second time, if it still doesn't....find another ride and leave it be, or fix it right. Full tune up, and glow plugs!