Here is a photo of a Bosch injector I’ve taken apart for cleaning. The tip of the nozzle had a bit of carbon buildup which I cleaned off with a carb cleaner and a brass wire brush. Only the tip of the needle that protrudes from the nozzle had some carbon which I cleaned with a tooth brush. The interior is quite clean and I’m surprised only 8 separate parts make up an injector(the spacer is on top of the spring), quite simple indeed. It seems the nozzle and needle are really the only moving parts that experience much wear. Should I first just replace the nozzles/needles and then have the injector tested or should I take all the injectors apart, clean them, put them together and then have them tested to see if any of the nozzles are bad? No need to replace a good nozzle since the car only has 130,000 miles.

Not much in them eh? Lots of engineering, I'd bet, though!

New nozzles will require re-setting the opening pressure (the shim below the spring is used to set this), and you cannot do this at home unless you have an injector tester. You might was well have the diesel shop put new nozzles in and adjust, it's going to cost you about the same either way, or do the exchange at FastLane.

I'd just pull the injectors and have a diesel shop test them -- if they need new nozzles, get them put in, otherwise just set the opening pressure.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!