Re: New injectors or just nozzles?
New nozzles alone would be an improvement over old worn nozzles BUT to get the full effect, there are quite a few other things to consider. In order for the nozzle to create an efficient spray pattern the rest of the injector needs to be in good condition. The injectors used in your 200tdi are Bosch two-stage injectors. They have a primary opening pressure and a secondary opening pressure, the idea being that the injector fires two shots of fuel into the cylinder as the piston is on its way up the cylinder compressing the fuel / air mix. These opening "pop" pressures need to be set correctly (primary 200 atmospheres) in order to get a good spray pattern and efficient penetration of the compressed air in the cylinder. A good diesel shop should be able to test them for you at ~£5-8 per injector. All that is usually required is a set of new nozzles, an ultrasonic clean of the internal injector parts and some shimming in order to set the pressures. I'd suggest that you find your local diesel specialist, call them and get them tested. If you're going to fit new nozzles, you might as well get them set correctly or you simply won't feel the full benefit.