My car is a 2004 S4 4.2

I removed my fuel rail in order to switch fuel injectors to diagnose a problem and I may have broken a few of them. On three of the injectors, a plastic washer-like object separated from the end of the injector.

My question: Are the injectors broken and need replacing? Can I stick the washer-like piece of plastic back on and expect it to work properly? Just wondering if anyone has any experience with this.

Here are some pictures:

Good injector:


Possibly broken injector:


Closeup of o-ring and washer-like plastic object:


Thanks in advance!

 

That is the o-ring retainer. It isn't necessary to have a sufficient seal but you risk the possibility of getting o-rings stuck next time they are removed.

Do they snap on firmly or are they loose? If they snap on pretty firmly, then I would re-assemble them and lube the o-rings up good for easy installation.

 

JHM stocks the B6-B7 S4 stock injector pintle caps.

Injector Pintle Cap (each) for B6-B7 S4 - JH Motorsports Inc. - -- JHM. Shifting you to the next