Pic of spare parts I got with my ZR-1 Purchase, injector questions ---

[alwayscode390]

I got the bag that was marked "8 Pri Set" (had 15 injectors in it ... Im thinking they are stock , and used because they are dirty), then a bag marked "8 2nd set" that looks to have 1 NEW injector (yellow and red cap on tip).

The old injectors are all marked "a" "b" ... seems Im missing 7B ... but they ended up with 1 extra new injector. I wonder what that's all about?

Seems "a" and "b" is "primary" and "secondary" ... but some of the ends look like they have a black plastic cap and o-ring , doesn't matter if they are A or B. Can you tell me which is primary and which is secondary by the tips?

Then I got a fuel pressure regulator, one straight PCV valve, and 7 injector (?) O-rings. All look new.

The only parts receipts I got was for the injectors and the FPR/PCV/O-Rings. All the parts were bought new in 2007 , Inectors Bosch part # 11115 secondary (0 280 150 556/561) , and # 11113 primary (0 280 150 556/561). They paid $675 for the 16 injectors.

I wonder why they installed injectors, but not the fuel pressure regulator? Just wanted spare stuff?

The plenum has to come off to see the injectors that are installed, right?

Just wondering if you guys had thoughts about whats going on. My car is running pretty good right now, but once in awhile around 3500 rpm it will stutter if I am not "ON IT" around those rpms ... and it was suggested I get new injectors , which I think I have installed right now.

Thanks ---