@ Diesel911 - I forgot to mention it in the first post, but I did indeed try the primer. I get the squishing/buzzing sound from the IP on the first pump, but just to be sure I gave it about 10 strokes, then tried to start. No change at all. So I guess that pretty much rules out losing prime, huh?

@ Charmalu - I do indeed live smack in the middle of road salt hell. And the car originated from DC, which probably isn't much better.

I'm far from experienced with this, but it surprises me that a glow plug problem wouldn't manifest itself even after a few hours of sitting during the day. Do you think the block heater would produce enough heat to make a difference in the morning if the glow plugs have problems?