Mercedes: engine wont start, battery selection, kansas city area

Question
I have a 1985 300 turbo diesel, 329,000. that was sitting for about 3 weeks in Kansas City area.  Went to start the engine and all it did was turn over.  After about 20 seconds smoke was coming out of the engine and exhaust but it didn't feel like it was going to start.  Turned like it does when the temperature drops below 5 degrees Fahrenheit but the temperature that day and two days prior were in the low 60's.  Please advise.   Thanks  

Answer
Answer:
This sounds like a weak/bad battery and/or bad starter.
A weak/bad alternator or voltage regulator could also be an issue.

Battery Safety
http://www.mercedesshop.com/shopforum/showthread.php?p=1057827

Battery selection / Charging System / jump starting / cold weather battery issues
http://www.mercedesshop.com/shopforum/showthread.php?p=1058189

Glow plugs link thread         
http://www.mercedesshop.com/shopforum/showthread.php?p=1019018

Starter health is important to your diesel!!!
http://www.mercedesshop.com/shopforum/showthread.php?p=739798

Gear reduction starter for W126 diesel?
http://www.mercedesshop.com/shopforum/showthread.php?t=148100

Tackling a starter, need suggestions (and sympathy)
http://www.mercedesshop.com/shopforum/showthread.php?p=1001659

"Alternator" 115 Amp Bosch AL129X works in 123s!
http://www.mercedesshop.com/shopforum/showthread.php?t=93569

Pictorial on Installing the Voltage Regulator
http://www.mercedesshop.com/shopforum/showthread.php?t=166105



Cold weather starting links
http://www.mercedesshop.com/shopforum/showthread.php?p=1018529