Just got some injectors, and seems the tip had been broke upon delivery. The plastic housing around the injector (where fuel squirts out) is broke, is it still useable?

 

If by "good" you mean "Can I drop it in as is?"

---- no.

You may be able to replace the cap, however.

 

thats just the pintel cap. the pintel still looks good.

 

How would I be able to replace the cap? That's the only damage, the others are fine

 

Either send out for servicing (most injector shops will rebuild them) or run it as is. I ran one like that for a while. Not ideal since there is a risk of dropping more plastic into the intake tract, but it works.

 

some are apparently not replaceable. DW told me there is no one has new pintel caps for the NB 99 red injectors.

 

Call your local NAPA, some do injector cleaning and testing. They may have the pintle cap you need or one close enough to use.