Ok i've read everything i can find in the old threads here but i see nothing directly referring to the cups the injectors seat in. Here's the question: Replace or not? Remove and clean?
I'm planning on replacing my injectors this weekend wit a couple friends helping me and i have been told by diesel mechanics if the cups don't come up with the injector there is no need to mess with them but i wonder about them. i don't want to make more work for myself or spend more money than i need to but i also don't want to do this again i'm sure once will be fun enough.

 

basically what they told you, if they dont pop out with the injector just leave them alone.

just make sure you clean the inside of the sleeve real well

 

Are the cups aluminum or stainless or maybe nickel? do you know?

 

i would just leave them in otherwise coolant will go in the cylinder