Alright, so this truck runs great but in the few days I've had it, sometimes it would smoke at idle and run rough. I was reading a lot of things on here about injectors and pumps etc and trying to narrow down the issue.
theres a few things that didn't make sense though. First of all, this truck starts instantly. This morning it was covered in ice and snow and fired up literally as soon as you turn the key. So I dont think anything is wrong with glow plugs or compression.

it run a little rough for a few seconds and cleared right up. Within a couple minutes the exhaust was clear as a bell. So I drive kids to school, and parked there waiting for a minute.
running absolutely perfect. No smoke, no misses, just perfect.
so I'm sitting there idling, and I heard something on the driver side it sounded like, almost like a heat blend door or a similar thud. Exactly when I heard that, it started running rough and smoking.
does anyone have a clue what's going on there?
I wasnt aware of any egr or any other type of system that it could be.
I definitely think the pump and injectors are in decent condition.
there is something else going on here.

 

Also with it running I removed the oil fill cap, cant notice any air movement but the engine is slightly warm.
I looked around the engine and firewall and I'm not sure what made the thud that made it start running rough. Theres the electronic throttle controller.
theres the cdr valve, but the exhaust smells like diesel not oil.

 

Also made up a wire with connector to the cold advance on the injection pump, it didnt change anything when supplied 12v from the battery.

I'm at a total loss here. I'm doing a ton of reading and finding theories that sound plausible except that my truck at times can run 100% perfect. I even considered maybe the injection pump is worn and out of spec, and the cold fuel and higher viscosity makes it run closer to spec...... but how can it go from running perfect to running like crap in 1 second flat?
That fact alone makes me wonder about the cold timing advance, but as I said when I jumped 12v to it, nothing happened.

every time I'm about to order injectors I get in and it's the best running idi I've ever been in.

is there any way that the drive gear on the injection pump is moving and falling in and out of time?

I've watched videos of idi trucks with bad injectors and I'd say mine seems that way when running rough, but it doesnt always run rough so I'm not sure I should replace things that seem fine sometimes.

 

Here's how bad it can smoke. You cant hear it well in the video but it's missing and running terrible.

and here it is running great early in the morning about -5

And here it is just running.

 

Get a return line kit from type4 and replace all the olives. Sounds like you're pulling air somewhere.

 

I forget what it is but it's something internal to the IP that can cause it to occasionally white smoke up a storm on cold start.I had a failing IP do this in the past too.Just like yours,otherwise most of the time it didn't do that but man when it did she sure set off a massive cloud lol.I replaced it with a good quality build (Moose IP) from the good folks out in Pennsylvania,over at Conestoga Diesel Injection and she's been running great since.
I have the truck intercooled and I went with the smoke puff limiter too so she runs clean and cool.

 

If you suspect it may be something sticking in the ip I would pull the filter drain it and fill it up with some diesel klean, start it up and let it run thirty seconds and then shut if off and let it sit overnight. A lot of people just use atf as do I anytime I change a filter on a diesel, but since your having problems the good stuff would be the way to go for now..

It definitely could be air intrusion, which aside from retarded timing is probably the #1 source for white smoke/haze, but it seems pretty intermittent for air intrusion, I'm trying to think what would cause it to come and go do randomly. Normally with air intrusion you also have cold starts problems or a stumbling shaking start and a drought idle for the first thirty seconds.

I'm kind of wondering if you don't have a sticky injector or two, as this seems the most likely the way it comes and goes and I bet the diesel klean overnight soak would probably help a lot as well, whatever I have left over from topping off the filter I pour in the tank. You could also add some atf as lubricant and give it a double dose. These are both cheaper than a pump or injectors by a long shot

 

Sounds like it could be the advance plunger sticking, my old pump had this problem i think. I advanced the timing until it ran well, but it was very advanced down low and very retarded up high. I second the notion of filling filter with ATF / diesel clean, run it to get it in the pump, then let it sit 24hrs or so.