Hey guys, I was reading through a bunch of threads already posted. Y'all seem to know what your're talking about. So I decided to go ahead and register, and ask a questions at the same time.

I acquired this 89 f250 7.3 non-turbo last march. As it is my first experience with diesels I'm a little newb-tarded... She has 322K on the clock, ran great all summer long. I did put a new fuel filter and air filter on it in May. Come fall, she started being a little moody, hard starts primarily, I attributed it to the cold vs diesel. That being said I went ahead and changed the glow plugs ( I don't know the brand, they're auto zones...) seemed to help a little. Well now that winter's in full swing here in Utah she's getting pretty cranky.
I noticed while driving she's starting to spit out more smoke than usual, from 1000 to 1600 ish rpm's it's real rough (almost like it's lugging the engine). There seems to be nothing wrong at all while just idling though. A mechanic buddy of mine (not diesel) also mentioned to me that I need a new throw-out bearing, but I dont' think that's part of this problem. The other morning she wouldn't start at all. I changed the fuel filter and filled the new one with diesel kleen. She fired right up and ran a lot better... for a minute... I just put some Heat fuel additive stuff into my tanks thinking maybe I'm getting water in the system somewhere. Also, I noticed the drain on the bottom of the filter (i'm told for draining water) does it only let water out? I ask, because if I open the valve when the truck is off, a little dribble of some fluid (doesn't appear to be water) comes out then stops. If I open it while the truck is running it's a steady flow.
I'm curious to know what else it could be? Again I'm a newb-tarded, so if I could get any responses "dumbed down" a little I would appreciate it.
Also, I should mention, she got an oil change in August; I put Delo 400Le in it. At the same time I drained and filled the transmission fluid.
I just changed the air filter again today too...