Thank you for your replies! Sorry that it took so long for me to respond -- I have been up to my eyeballs lately
JimSmith, good hypothesis about the air leakage & reduction of volume of the air bubble when cold. The suction lines are in good shape and not leaking as far as I can tell, however I think it would be prudent for me to replace them anyways considering the age of the car. The next time the engine is very hot, I will go under the hood and use the manual pump to see if any air bubbles present themselves in the return line.
This being my first diesel, I'm not sure exactly how fast the starter should spin the engine over. I will try to take notice of whether it seems slower when the engine & starter windings are hot.
Mreid, I believe that the glow plugs are functioning correctly, however the light on the dashboard does not directly correlate with when the glow plugs are actually receiving voltage. I will hook up a test light directly to one of the glow plugs to check their functioning when the engine is hot.
I hope to be able to poke around at this later this week -- Thanks again guys for the assistance!