Now it may seem dumb, but I'll ask anyway. Are the primary and secondary fuel injectors different, or are they the same, but just in different places? Also (and I think I know the answer) if the computer is stock, the injectors have to be stock as well right? Otherwise it would run rich right?
I'm trying to replace old injectors because I think they are leaking. I've been getting "hot starts" and I replaced the spark plugs after a particular difficult day (it wouldn't start, even cold), and the old ones were completely soaked. I pulled them, cranked it for a while with the fuel and ignition fuse pulled, and eventually got it started. It runs now, but still doesn't quite want to start when it's hot. Everything points to old leaky injectors, so I just need to know what to get. I bought some from rockauto, but it didn't specify primary, secondary, or even the flow specification, just fuel injectors for an '88 rx-7 1.3 turbo.

 

Assuming they're stock 550cc injectors, yes, they're all the same. A stock ECU would be a good indicator that the injectors haven't been swapped, along with them all having the same color/shape.

A cheaper option for you would be to have your existing injectors serviced for around $17 each (witchhuner, RC engineering, etc...). Even though the place you bought these new ones from say they're for a turbo, I think I'd want to verify that they're actually 550cc too. The places I mentioned also flow test.