2005 S60 2.5T fuel injector question
 

I have narrowed down a cylinder failing to fire to the fuel injector. I determined the fuel injector electrovalve is doing its job. So I believe it is plugged. The question is should I remove and clean the plugged injector or replace all five injectors on this otherwise well maintained 220,000 mile engine? Would new injectors be a better approach for improved fuel efficiency and service life in terms of unburned fuel affecting cylinder wall / ring wear?

there are services that clean injectors (most use an ultrasonic cleaning process) - just google "fuel injector cleaning services" to look for a shop near you or do mail away if you don't need the car as a daily driver. Otherwise, did you try throwing in injector cleaner like Techron into the gas or run a few tanks of brand name premium? If you injector is clogged, I'd think you'd have a lean burn, not unburnt fuel. What is the color of the spark plug? If you have a black plug you could have an ignition coil issue or a compression issue.

Thank you Moderator. I appreciate your advice. I initially suspected the coil pack. I swapped coils from a cylinder that was firing to the dead cylinder and eliminated a coil pack as the culprit. I unplugged the injector on the dead cylinder and connected a battery to a momentary switch with engine off. Triggering the switch on and off I could hear the electrovalve function. I will now locate a fuel injector shop for cleaning or replace with new. Cost will determine which way I go. Thanks again