I damaged 2 of the O-rings (long story), and factory style ones don’t seem to seal well with my Vishnu fuel rail. The factory ones are loose on the injector. The ones that came with the injectors are not.

What OE O-rings work with them?

 

go to the autoparts store, its just an O-ring, they'll probably just give them to you for free. (NAPA did for me once)

 

I thought they needed to be special for-fuel or Viton O-rings?

 

Just call or email them. I bet they throw them in the mail unless you need them ASAP.

 

They do need to be Viton. That said, they should have them.

 

always can measure them and get a massive bag on McMaster for like $5. I have a bag of Viton Orings for stock mazda/honda/import bosch style injectors. Bought it like 5 years ago and I still have like 75 left in the bag at least. I just keep it in my tool box.

 

McMaster FTFW! I just recieved a lifetime supply (25) of CAS O-rings for 15 bucks.

 

Mike Deatsch emailed me back and said I could probably use 2002+ WRX O-rings.

Interestingly, Rockauto says "GB 8024A" which also fits "Mazda 1984-2007".

I then looked at 2000 Mazda miata and it does use the "GB 8024A" and several others, including the Felpro ES70600 miata O-rings which I tried yesterday which didn't seal.

Several other auto parts websites say the ES70600 fit the miata but not the WRX. So far no other online sites have O rings for the WRX.

 

I know you have a caliper from previous threads, will you please measure the ID, OD, and thickness of an known good oring that you have in your possession? I will then link you to the mcmaster PN that you need so that you don't have to keep this going.

 

It's hard to accurately measure O ring i.d. and o.d.

Instead I'll measure the diameter of the injector neck on which the Oring sits, and the Oring thickness. I reckon the Oring i.d. needs to be slightly smaller than the first number.

RC: 7.8mm, 2.25mm
94 factory: 8.0 mm, 2.0mm

Deatschwerks injectors later, they're in a shop.

 

Did you get this sorted?

 

Yes I did, thanks, I ended up re-using some O-rings from various miata injectors.

My problem turned out to be

1) I ham fisted them in, despite having done this 3x before, see (2) below
2) that the prototype Vishnu fuel rail (from way back in 2001), is subtly different than stock and for some reason the Deatschewerks injectors seem to be a bit fiddlier to plug them in without damaging the O rings) then RC injectors.

For posterity's sake ... my caliper battery died right when I was gonna measure the required i.d. on the Deatschwerks injectors, but it looks like 2.0 mm O-rings witih 7.6 mm i.d. will work.

These ones may work too:
http://www.mcmaster.com/#metric-o-rings/=6qwoui

For my Vishnu rail (don't know if this is true for later production or FM-sold units), the O-rings had to be snug on the injector and not loose, else they'd tend to catch on the rail while being plugged in.

 

I have the same rail and RC550s. the RCs have two plastic spacers that sandwich the o-ring. RC has since moved to aluminum spacers because the plastic ones eventually get loose and fall off. Imagine my frustration when I found that out upon reassembling! Thankfully they sent me the aluminum replacements.

As I recall, the o-rings weren't snug but were captured well between the spacers.