I've been sorting through all the issues with my new chassis, of which leaking injectors was one. There were large brown fuel varnish stains around the manifold, so I pulled the injectors and went shopping for new seals. I could find the oring and grommets for the fuel rail side - but not the insulators (the things that look like tractor tires and insert into the manifold). Only Mazda has them. Odd for a 20 year old car.

Tonight I was looking at an old insulator and decided to tear one apart. What I found was that the insulator is two pieces - the hard ring with the ribs, and a soft interior piece that's (nearly?) identical to the grommet used on the fuel rail side of the injector. So I took a new grommet and inserted into the insulator's hard ring - perfect fit. I'm not sure if that's the intention or a coincidence, but nothing is mentioned in the 92 FSM about it. I'll try it out on the car and see if there's a problem, but I can't imagine there would be.

Injector with the "three" parts installed, and free:


and the insulator disassembled, hard ring below, soft "grommet" up top