The hard starting with white smoke and such can also be caused by a set of worn out injectors.

The occasional timing code is not a good sign though.

The ECM will adjust the injection timing though a fairly broad range before it complains.

Before spending the big $$$ for a gear set, I would suggest getting the Squirts checked.

A strong diesel smell when warm is sign of bad injectors.

If its a timing issue, the computer would complain bitterly.

Hard cold starts, aside from bad glow plugs are directly connected to low pop pressure and a set of injectors that are Peeeeing a stream rather than a fine mist upon entering the injection cycle.

This is a commonly overlooked problem which usually ends up with folks blaming the glow plugs.

If your injectors are at 100K miles or more, they are suspect.

With a set of squirts that are in good shape, these engines will start with minimal smoke even with half the glow plugs non functional.

A long period of cranking followed by tons of white smoke and a period of time that the engine misses on a few holes, then followed by a strong pungent exhaust odor even when warm points more towards injectors than timing gears/chain.

Having a timing set, either gears or chain and sprockets that's in good order is a plus for sure, and all the materials mentioned are definately spot on, I would still check your squirts before stepping up for the timing set.

FWIW
I have replaced chains on these and retained the original sprockets many many times. The sprockets are HARD and dont seem to wear.

The chains stretch in time and as Jim mentioned, start to cause issues.

I have seen engines with 250K miles and a chain that was looser than a rat tail in a rain barrel still run good without complaints.


Missy