Before adjusting the ALDA make sure that all the pressure lines are clear. The most common culprit of problems is the banjo fitting on the rear of the exaust manifold. If it gets clogged, the alda will recieve a false reading and will restrict fuel as not to create an overboost situation. These old cars make smoke for a variety of reasons. On my 84 300td I spent way too much time messing around with the ALDA. I had the same symptons that you described. The adjustment will only work as a fine tuning and likley will not fix your smoking problem alone. I would change filters, do a valve adjustment and pull the injectors and clean them along with all fuel lines. The one single thing that made the biggest difference was to take the car our on a long hard run and blow out all the crud that collects in the intake manifold. I drove mine about 200 miles. When I pulled out of my driveway (Running the rpms high) I put out a cloud of smoke that stopped traffic. By the end of the roadtrip the car did no smoke at all. Short trips and not letting thse engine warm up allows the intake to get clogged. Hope this helps.