Fuel injectors: DIY service tips

My Beneteau Oceanis 381, Sacha, is nearly 20 years old. Her engine is a Volvo Penta MD22, which is an old fashioned 4-cylinder Perkins-derived diesel engine. It has done 3,250 hours running time and is still going strong, using only about a litre of oil per season of about 120 hours running.

But last year I noticed it was vibrating a bit at low revs and blowing lots of grey/black smoke out of the exhaust under load and at high revs.

I tested each injector in turn and concluded that two of them were functioning poorly, but decided to pull, check and service them all.

After removing the injectors, I