1999 Isuzu 3.0 injectors
 

Hello everyone I have a few questions I hope someone can help me with.
I have a 1999 trooper 3.0 injector 2 is reading low according to the garage which is causing it to misfire.
I live in torfean wales and am looking for somewhere that can check and referb the injectors or if it’s possible to strip the injectors and clean and replace worn parts myself if that’s possible?
I have sent the injectors to 2 companies already and they have sent them back saying that they cannot test this type of injector so I am stuck.
any help would be greatly appreciated