Smokin
 

Recently my truck started to idle a little lower and a little rougher, and at the same time it is blowing a white/grey smoke at idle. It seems to run good going down the road and the smoke clears up for the most part. Although if I get on it more than half throttle going up a hill it will smoke black, not a lot but It never used to smoke at all. About two weeks ago I mixed three gallons of used motor oil in with a full tank, filtered through coffee filters. I dont know if this has anything to do with my problem. Also there is a single wire on the bottom of the pump that I noticed was unplugged, so I plugged it in and soon after is when the problem started. I am relatively new to diesels and this is the first problem this truck has given me so any ideas would help.

the waste motor oil will make more black smoke and it will make your truck smoke blue cold and smell like it's burning oil

Try unplugging that wire that you connected. See if the problem goes away.
If it does - leave the wire unplugged.

I have unplugged the wire and it has not fixed the problem yet. All of the wmo has been burned up and I have since burned a 1/2 tank of straight diesel. Could it be a problem with an injector?

I am having a similar issue. My thought was that the little horizontal pin that rides on the fuel pin was stuck and since recently I have been luricating my pump with Power Service and 2 stroke oil, that I freed the little pin and my AFC is now working properly. ( I really cranked up the Starwheel awhile ago). I will check tonite to see if the pin is free, unfortuneatly before I adjusted the AFC and the pin I did not check to see if the little pin was free. Does this sound feasible to anyone?

Sound like not enough fuel...
The pin that rides on the fuel cone could be stuck IN - ie not coming out far enough when the fuel cone drops.
ER ---
Check the hose and connections from the engine to top hat. If that little line leaks or is bent your fuel cone wont move at all...