I'm not sure if this is the correct sub forum but here goes. A few years ago I installed an aftermarket ECU in my track only '87 NA with a "hybrid" engine, it was assembled from parts I had available and I was told it would be a good, durable setup. It is S5 housings, irons and rotors with an S4 intake. In the tuning process with the new ECU system, the shop I was using suggested getting RX 8 "Yellow" injectors and I somehow found O-rings and grommets that fit well enough for it to not leak. Unfortunately I did not keep any notes on what I used. I had the engine rebuilt this winter and I now cannot find the proper combination of O rings and grommets. I have tried many combinations with the latest being RX 7 O rings and grommets on the upper part of the injector and RX 8 grommets on the bottom and they are soooo close to being correct but still leak. Does anyone else run RX 8 injectors in an FC engine? Which O Rings and grommets do you use? Thanks

 

where are they leaking? primaries or secondaries? both?

The secondaries seem to fit tighter than the primary ones. This is how I ran my setup on non turbo stock manifolds/rails using rx8 yellows.

1. Injector O-ring = rx8
2. Injector upper grommet = rx7
3. Injector lower grommet = rx8

no vac leaks here