Injectors: Grommets, Orings & Insulators [Archive] - MX5 Miata Atlanta Owners Club
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FE3tMX5
07-09-2009, 10:24 PM
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:
http://i158.photobucket.com/albums/t86/m2cupcar/injectorseals1_640.jpg

and the insulator disassembled, hard ring below, soft "grommet" up top
http://i158.photobucket.com/albums/t86/m2cupcar/injectorseals2_640.jpg
LagunaRoadster
07-09-2009, 11:25 PM
Well, if you do decide to order said grommets, I recommend here:
http://finishlineperformance.com/

Just search injector, and viola! Though a set is 29.95 ... :(
MoD_Scotty
07-10-2009, 12:51 AM
$30?! Ouch. I accidentally destroyed one...and replaced it with a grommet I had laying around the garage. It might eventually need to be replaced, but it's been about 5,000mi so far with no problems.
FE3tMX5
07-10-2009, 08:29 AM
Just search injector, and viola! Though a set is 29.95 ... :(

Hmmm... I paid $19 for the insulators in grommets from Mazda. Maybe they made a mistake.

Just thought I'd provide an alternate solution for the right situation. Having race these cars for 15 years, I have had these go bad regularly from the heat, and wished I'd figured this out way back. Silly me.