Will not start
 

Recently purchased 85 300DT with 114K miles. Car sat up for ~ 1.5 years prior to purchase. Bought new battery and added fuel. Drove for ~ 300 miles over a period of several days and then added fuel additive and filled the tank. Drove another 50 miles the next day. She drove perfectly. Got up the next morning (temp 30 degrees) and she would not start. Haven't been able to start since. Noticed the manual fuel primer pump appears to be in the UP position. Any ideas on why she will not start? Visual of fuel in pre-filter shows little to no sludge. Any help appreciated.

Try pumping the manual pump some and see if you are getting any leakage. The pump handle should be down and "locked" by turning clockwise. You will probably want to start doing some trouble shooting. I would strongly suggest changing both filters if you have not already done so.

This is most likely glow plug related. Start your troubleshooting by following Jims suggestions and pump the primer until you hear a hissing at the top of the main fuel filter, then push the pump down and turn clockwise until it is snug.

Then, loosen a line at an injector about one turn and have an assistant run the starter motor while you observe the injector fitting. Fuel should come out whenever the starter is turning over the motor. If fuel does come out, retighten the fitting and turn you attention to the glow plug system. If fuel does not come out, make sure you indeed have fuel getting to the pump and have bled the system thoroughly.

Once you turn to the glowplug system, put a voltmeter on one of the glow plugs and turn on the key. If there is voltage on the glow plug, then replace the glow plug. If there is no voltage at the glow plug, check the bar shaped fuse in the glow plug relay on the drivers side wheel well. Loosen both screws and look at the ends of the fuse. They will sometimes vibrate in half, but appear to be okay.

Good luck,