I got my injectors back from rc engineering, and 2 are labeled "high resistance" and the other 2 are labeled "low resistance", so which are the primaries and secondaries?

 

uhh, correct me if I'm wrong (which I probably am) if your car is a S4 you need resistors on the high resistance injectors for them to work, and possibly if your car is a S5 then you need them on the low resistance..
unless you have a aftermarket ECU or something.. but I always though all 4 were the same, either high or low depending on your rx7 model.. if so and your car is stock you may have recieved the wrong injectors back??

 

I bought some used injectors from somebody, I guess they must of came from an S5....

So they won't work?

 

Well the adding/right answer is....
IF you have an 88(technically87.5+) then you are high impedance.
If you have a 87.5 and lower year then you are low impedance.

You can verify two ways. The notch offset on the harness(only one type will plug right in/high or low) or you can look under your airfilter for a small resistor pack.

If you are low impedance then all you have to do is add one 10ohm by 10watt resistor inline to each HIGH impedance injector.
If you are high impedance then you need to remove the stock resistor to alllow high flow to the high impedance injector.

www.rotaryresurrection.com has a tech section on this.

BTW you woudl know of it came out of an S5. They look competely different. They have oval style plugs instead of the square styles. S4's use.

 

hmm so they are infact both from s4's then, cause all 4 have square plugs. Why would RC Engineering label 2 as high resistance and 2 as low resistance?!?! I am boggled.

Here is the story though...

I had an engine fire, and 2 injectors ended up burning to a crisp. So I bought 2 used ones, but I kind of forgot about my rx7 for a while, so the card and injectors were sitting in the garage for 5 months. when I finally got all the parts and such and put it together, the primary injectors wouldn't feed fuel, I took the spark plugs out and made sure everything was primed, and when I turned there was no "fuel mist" coming from the spark plug holes.

So I sent the injectors to get rebuilt. So I guess I will just put it together and see if it works.

 

Its going to burn out your ECU.. You need to determine if you have a low impedance system or a high impedance ECU.

If you have a high impedance ECU, and low impedance resistors, you can match them using 10watt 10 OHM resistors.