I just got my 1.8L swap running in the last week or so. I used RX-8 yellow injectors for my build, and noticed a vacuum leak at one of the injector seals to the cylinder head. I sprayed brakeclean at the seal when at idle, and could hear idle speed change, and saw the engine go rich on the Wideband sensor.

I remember when I was assembling the fuel rail - I used brand new (parts store aftermarket) injector seals, and they seemed really loose on the RX-8 injectors. Not exactly hot-dog-in-a-hallway loose, but certainly looser than the stock injectors.

Since I used brand new seals, what should I do to fix this issue? Buy a different brand of seals?? Use rtv during installation? Add a extra O-ring to the stackup?

 

You could double check this but I seem to recall FM turbo install directions saying that stacking two could be done. I can't remember if that was in reference to auto parts store Mazda seals or generic Ford seals that could be substituted.

 

If you had the huge stock pintle type injectors, and you went to the Bosch type (rx 8 injectors), the grommets are slightly different. Use grommets that were on '99 stock injectors.

 

Ahh - sounds like this is my problem. I am using the seals from a NA 1.8L. Looks like I need NB seals.