On the glow plugs.... with the car warm, the battery, cables , and starter good....I feel the car should start even with no glowplug activity.... that is why I have been focused on fuel ......

my experience indicates otherwise. last summer, va. 90 degrees. the 83 300dt would not start. did not grind and grind. but did spin the bugger for at least 30 sec. replaced glow plugs. subsequent starts - immediate. by 2 cents.