Injectors

You can pull them out and get them done or take them to diesel place and have them done. The 2h injectors are rebuildable usually unless very badly worn.
A cheap and dirty solution to your problem (excessive smoke I presume) is to fill it with biodiesel and take it for a run, no smoke and it should pass an emissions test, but a bit naughty and as soon as you put dinodiesel in the smoke will be back.
whereabouts are you located so people can refer you to local diesel place?
The other way to go is to buy exchange/reco injectors.

You could try the CEM products to clean out your rings etc and use their fuel additive.

This could do the trick.

I think if the injectors have not been done for 100000k's then it is well worth the investment. It will go better and use less fuel. And no black smoke.

The 2h injection pump is both centrifugal governor and diaphragm controlled. The diaphragm on these (now a wee bit elderly) are known to split to give the sort of over fuelling (excess smoke) problems you describe.
Unless you know how to pull the end off the pump, take it to an injection bloke who can.
Non of these things are difficult, but you need the tools and to have been there before.
My opinon - 2h- bloody good engine.
kesh

Staying in on topic and being helpful:

I had the injectors and pump on my 2H done about 18 months ago by JC Diesel in Sydney. Cost about $800. Dropped the car off and picked it up that night. Would be cheaper if you did bits of it yourself like Peter suggests but hard to do they dyno bit at the end I recko.

Stopped the smoke, engine ran with more power and increased fuel economy by 10% so paid for the work in a year. Well worth doing.

Injectors are 60-70 dollars each fitted and they will usually have a look at the pump while they are at it so between 4-500 dollars

Lisa

I would suggest the following three ways to solve the problem which is basically a lack of full combustion in the trusty engine which can be caused by overfueling or lack of air and conversely low compression from worn or clogged rings.

You don't mention if the vehicle performs as usual or has become sluggish but the following would still apply

1. Before doing anything, I would check the air filter to make sure it is clean and free flowing.
These diesels need plenty of air and if the filter is old and or blocked that could be cheap a fix.
I mentioned 'old' as some filters can swell imperceptibly over time and decrease air flow. Dare I say it but some service centres may charge you for replacing filters but not actually do it to maximise their profits,

2. The 2H, whilst a reliable old motor, is notorious for having a problem with clogged rings if not serviced regularly and like wise glazing if not given a good work out every now and then - only you know how it is used!
If the rings are clogged, which can often be the case with diesels not working hard then the commercial clean out of the engine would be the go - its amazing how much sludge they actually are able to remove from a working motor and the system cleans the injectors at the same time however it does not improve worn nozzles.
A good work out in the scrub with high load and plenty of soft sand wouldn't hurt the old girl either.

3. If you have eliminated the above as the problem and its a hard worker I would consider the injectors might need attention however if its a shopping trolly I would immediately look at the air filter, oil change periods and glazing.
Injectors will probably cost $60-100 each and they will always touch you up for a fuel pump rebuild so expect a $1000 bill. If that's the path you go down then have the compression checked when they do the service as the real answer will lie there.

Eliminate the obvious before proceeding to the expensive.

Good Luck

John G