Big puff of smoke when starting

Most diesel engine smoke when starting, the fuel isn't being burned efficiently at the start.

 

Faulty injector(s), do you smell raw duel when starting it or black smoke without the fuel odor?

 

I stand outside when starting a truck on occassion just to watch the stacks. If the engine isn't missing at all when starting, I doubt there is anything worth fixing. I used to run farm tractors, the older ones were set up so you could see the smoke because the exhaust was piped out as soon as possible. They have moved the stacks on the newer tractors out of sight.

I can give examples of a 4440 John Deere and compare to a 4840, same size engine in displacement but more power in the 4840, kind of like comparing your 550 to a 435. The 4840 always smoked more on starting, but it ran better, although idle after starting was rough. The pump and injectors were set up to flow more fuel when horsepower was called for.

The electronics in the 'e' engines and newer farm tractors as well, are supposed to reduce the smoke. Fuel is supposed to be cut off more if it is outside the pressures needed for clean burning, more pressure means finer particles and less black smoke. If you are worried about it, you need to talk to a Cat mechanic. How many hours(miles) on the engine?

 

Sounds like a possibility, is it a3406e?